Number System Competitive Exams
100 questions · Mathematics
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Question 1 of 100
What is the unit digit of 8^14?
ExplanationUnit digits follow a cyclicity of 4. Power 14 divided by 4 leaves remainder 2. Unit digit is 4. Tip: Memorize cyclicity of 2, 3, 7, 8.
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Question 2 of 100
What is the difference between the place value and face value of 9 in 29850?
ExplanationPlace value = 9000, Face value = 9. Difference = 8991. Tip: Place value depends on position, face value is the digit itself.
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Question 3 of 100
What is the cube of 7?
Explanation7 * 7 * 7 = 343. Tip: Memorize cubes up to 15 for competitive exams.
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Question 4 of 100
Identify the nature of the number 44:
Explanation44 is a Composite number. Prime numbers have exactly two factors (1 and themselves). Composite numbers have more than two factors.
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Question 5 of 100
What is the sum of the first 35 odd numbers?
ExplanationFormula: n^2. Here n=35, so 35^2 = 1225. Tip: Sum of first n odd numbers is always a perfect square.
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Question 6 of 100
If a=42 and b=43, evaluate (a+b)².
Explanation(a+b)² = 7225. Tip: Use algebraic identities for faster calculations.
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Question 7 of 100
What is the cube of 8?
Explanation8 * 8 * 8 = 512. Tip: Memorize cubes up to 15 for competitive exams.
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Question 8 of 100
What is the unit digit of 4^37?
ExplanationUnit digits follow a cyclicity of 4. Power 37 divided by 4 leaves remainder 1. Unit digit is 4. Tip: Memorize cyclicity of 2, 3, 7, 8.
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Question 9 of 100
What is the sum of the first 29 even numbers?
ExplanationFormula: n(n+1). Here n=29, so 29x30 = 870. Tip: Sum of even numbers is n(n+1).
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Question 10 of 100
Identify the nature of the number 51:
Explanation51 is a Composite number. Prime numbers have exactly two factors (1 and themselves). Composite numbers have more than two factors.
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Question 11 of 100
What is the difference between the place value and face value of 5 in 30050?
ExplanationPlace value = 50, Face value = 5. Difference = 45. Tip: Place value depends on position, face value is the digit itself.
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Question 12 of 100
Which of the following is a rational number?
Explanation√25 is rational because it evaluates to a whole number. Irrational numbers cannot be expressed as p/q.
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Question 13 of 100
If a=20 and b=43, evaluate (a+b)².
Explanation(a+b)² = 3969. Tip: Use algebraic identities for faster calculations.
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Question 14 of 100
If a=31 and b=46, evaluate (a+b)².
Explanation(a+b)² = 5929. Tip: Use algebraic identities for faster calculations.
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Question 15 of 100
What is the sum of the first 22 odd numbers?
ExplanationFormula: n^2. Here n=22, so 22^2 = 484. Tip: Sum of first n odd numbers is always a perfect square.
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Question 16 of 100
If a=41 and b=19, evaluate (a+b)².
Explanation(a+b)² = 3600. Tip: Use algebraic identities for faster calculations.
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Question 17 of 100
Which of the following is a rational number?
Explanation√4 is rational because it evaluates to a whole number. Irrational numbers cannot be expressed as p/q.
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Question 18 of 100
What is the sum of the first 14 odd numbers?
ExplanationFormula: n^2. Here n=14, so 14^2 = 196. Tip: Sum of first n odd numbers is always a perfect square.
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Question 19 of 100
What is the unit digit of 3^31?
ExplanationUnit digits follow a cyclicity of 4. Power 31 divided by 4 leaves remainder 3. Unit digit is 7. Tip: Memorize cyclicity of 2, 3, 7, 8.
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Question 20 of 100
What is the sum of the first 30 odd numbers?
ExplanationFormula: n^2. Here n=30, so 30^2 = 900. Tip: Sum of first n odd numbers is always a perfect square.
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Question 21 of 100
What is the difference between the place value and face value of 7 in 30074?
ExplanationPlace value = 70, Face value = 7. Difference = 63. Tip: Place value depends on position, face value is the digit itself.
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Question 22 of 100
What is the difference between the place value and face value of 2 in 60027?
ExplanationPlace value = 20, Face value = 2. Difference = 18. Tip: Place value depends on position, face value is the digit itself.
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Question 23 of 100
What is the cube of 6?
Explanation6 * 6 * 6 = 216. Tip: Memorize cubes up to 15 for competitive exams.
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Question 24 of 100
What is the sum of the first 24 even numbers?
ExplanationFormula: n(n+1). Here n=24, so 24x25 = 600. Tip: Sum of even numbers is n(n+1).
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Question 25 of 100
Which of the following is the smallest prime number?
Explanation2 is the smallest and the only even prime number. 1 is neither prime nor composite.
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Question 26 of 100
What is the unit digit of 2^29?
ExplanationUnit digits follow a cyclicity of 4. Power 29 divided by 4 leaves remainder 1. Unit digit is 2. Tip: Memorize cyclicity of 2, 3, 7, 8.
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Question 27 of 100
Identify the nature of the number 7:
Explanation7 is a Prime number. Prime numbers have exactly two factors (1 and themselves). Composite numbers have more than two factors.
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Question 28 of 100
What is the sum of the first 18 even numbers?
ExplanationFormula: n(n+1). Here n=18, so 18x19 = 342. Tip: Sum of even numbers is n(n+1).
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Question 29 of 100
Which of the following is an irrational number?
Explanation√11 is irrational because its decimal expansion is non-terminating and non-recurring. √ of perfect squares are rational.
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Question 30 of 100
What is the sum of the first 35 even numbers?
ExplanationFormula: n(n+1). Here n=35, so 35x36 = 1260. Tip: Sum of even numbers is n(n+1).
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Question 31 of 100
Which of the following is an irrational number?
Explanation√2 is irrational because its decimal expansion is non-terminating and non-recurring. √ of perfect squares are rational.
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Question 32 of 100
What is the sum of the first 34 even numbers?
ExplanationFormula: n(n+1). Here n=34, so 34x35 = 1190. Tip: Sum of even numbers is n(n+1).
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Question 33 of 100
What is the cube of 13?
Explanation13 * 13 * 13 = 2197. Tip: Memorize cubes up to 15 for competitive exams.
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Question 34 of 100
What is the sum of the first 22 even numbers?
ExplanationFormula: n(n+1). Here n=22, so 22x23 = 506. Tip: Sum of even numbers is n(n+1).
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Question 35 of 100
What is the difference between the place value and face value of 6 in 46382?
ExplanationPlace value = 6000, Face value = 6. Difference = 5994. Tip: Place value depends on position, face value is the digit itself.
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Question 36 of 100
What is the sum of the first 26 odd numbers?
ExplanationFormula: n^2. Here n=26, so 26^2 = 676. Tip: Sum of first n odd numbers is always a perfect square.
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Question 37 of 100
Which of the following is a rational number?
Explanation√9 is rational because it evaluates to a whole number. Irrational numbers cannot be expressed as p/q.
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Question 38 of 100
What is the cube of 15?
Explanation15 * 15 * 15 = 3375. Tip: Memorize cubes up to 15 for competitive exams.
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Question 39 of 100
Which of the following is the smallest prime number?
Explanation2 is the smallest and the only even prime number. 1 is neither prime nor composite.
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Question 40 of 100
If a=50 and b=22, evaluate (a+b)².
Explanation(a+b)² = 5184. Tip: Use algebraic identities for faster calculations.
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Question 41 of 100
What is the sum of the first 40 odd numbers?
ExplanationFormula: n^2. Here n=40, so 40^2 = 1600. Tip: Sum of first n odd numbers is always a perfect square.
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Question 42 of 100
What is the cube of 12?
Explanation12 * 12 * 12 = 1728. Tip: Memorize cubes up to 15 for competitive exams.
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Question 43 of 100
What is the cube of 11?
Explanation11 * 11 * 11 = 1331. Tip: Memorize cubes up to 15 for competitive exams.
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Question 44 of 100
What is the sum of the first 21 even numbers?
ExplanationFormula: n(n+1). Here n=21, so 21x22 = 462. Tip: Sum of even numbers is n(n+1).
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Question 45 of 100
What is the sum of the first 35 natural numbers?
ExplanationFormula: n(n+1)/2. Here n=35, so 35x36/2 = 630. Tip: Always remember the sum of first n natural numbers formula.
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Question 46 of 100
If a=16 and b=12, evaluate (a+b)².
Explanation(a+b)² = 784. Tip: Use algebraic identities for faster calculations.
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Question 47 of 100
What is the sum of the first 45 natural numbers?
ExplanationFormula: n(n+1)/2. Here n=45, so 45x46/2 = 1035. Tip: Always remember the sum of first n natural numbers formula.
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Question 48 of 100
Identify the nature of the number 45:
Explanation45 is a Composite number. Prime numbers have exactly two factors (1 and themselves). Composite numbers have more than two factors.
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Question 49 of 100
What is the sum of the first 29 odd numbers?
ExplanationFormula: n^2. Here n=29, so 29^2 = 841. Tip: Sum of first n odd numbers is always a perfect square.
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Question 50 of 100
What is the sum of the first 25 natural numbers?
ExplanationFormula: n(n+1)/2. Here n=25, so 25x26/2 = 325. Tip: Always remember the sum of first n natural numbers formula.
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Question 51 of 100
What is the sum of the first 19 even numbers?
ExplanationFormula: n(n+1). Here n=19, so 19x20 = 380. Tip: Sum of even numbers is n(n+1).
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Question 52 of 100
What is the unit digit of 2^19?
ExplanationUnit digits follow a cyclicity of 4. Power 19 divided by 4 leaves remainder 3. Unit digit is 8. Tip: Memorize cyclicity of 2, 3, 7, 8.
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Question 53 of 100
Which of the following is a rational number?
Explanation√25 is rational because it evaluates to a whole number. Irrational numbers cannot be expressed as p/q.
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Question 54 of 100
What is the sum of the first 37 even numbers?
ExplanationFormula: n(n+1). Here n=37, so 37x38 = 1406. Tip: Sum of even numbers is n(n+1).
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Question 55 of 100
If a=14 and b=39, evaluate (a+b)².
Explanation(a+b)² = 2809. Tip: Use algebraic identities for faster calculations.
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Question 56 of 100
Identify the nature of the number 13:
Explanation13 is a Prime number. Prime numbers have exactly two factors (1 and themselves). Composite numbers have more than two factors.
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Question 57 of 100
Identify the nature of the number 29:
Explanation29 is a Prime number. Prime numbers have exactly two factors (1 and themselves). Composite numbers have more than two factors.
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Question 58 of 100
Which of the following is the smallest prime number?
Explanation2 is the smallest and the only even prime number. 1 is neither prime nor composite.
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Question 59 of 100
What is the cube of 5?
Explanation5 * 5 * 5 = 125. Tip: Memorize cubes up to 15 for competitive exams.
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Question 60 of 100
Which of the following is an irrational number?
Explanation√2 is irrational because its decimal expansion is non-terminating and non-recurring. √ of perfect squares are rational.
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Question 61 of 100
Identify the nature of the number 53:
Explanation53 is a Prime number. Prime numbers have exactly two factors (1 and themselves). Composite numbers have more than two factors.
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Question 62 of 100
Identify the nature of the number 56:
Explanation56 is a Composite number. Prime numbers have exactly two factors (1 and themselves). Composite numbers have more than two factors.
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Question 63 of 100
What is the sum of the first 12 odd numbers?
ExplanationFormula: n^2. Here n=12, so 12^2 = 144. Tip: Sum of first n odd numbers is always a perfect square.
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Question 64 of 100
What is the difference between the place value and face value of 3 in 70308?
ExplanationPlace value = 300, Face value = 3. Difference = 297. Tip: Place value depends on position, face value is the digit itself.
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Question 65 of 100
What is the unit digit of 8^43?
ExplanationUnit digits follow a cyclicity of 4. Power 43 divided by 4 leaves remainder 3. Unit digit is 2. Tip: Memorize cyclicity of 2, 3, 7, 8.
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Question 66 of 100
If a=40 and b=50, evaluate (a+b)².
Explanation(a+b)² = 8100. Tip: Use algebraic identities for faster calculations.
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Question 67 of 100
What is the sum of the first 20 natural numbers?
ExplanationFormula: n(n+1)/2. Here n=20, so 20x21/2 = 210. Tip: Always remember the sum of first n natural numbers formula.
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Question 68 of 100
What is the difference between the place value and face value of 6 in 86977?
ExplanationPlace value = 6000, Face value = 6. Difference = 5994. Tip: Place value depends on position, face value is the digit itself.
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Question 69 of 100
Which of the following is the smallest prime number?
Explanation2 is the smallest and the only even prime number. 1 is neither prime nor composite.
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Question 70 of 100
Which of the following is the smallest prime number?
Explanation2 is the smallest and the only even prime number. 1 is neither prime nor composite.
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Question 71 of 100
What is the sum of the first 27 natural numbers?
ExplanationFormula: n(n+1)/2. Here n=27, so 27x28/2 = 378. Tip: Always remember the sum of first n natural numbers formula.
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Question 72 of 100
What is the sum of the first 28 even numbers?
ExplanationFormula: n(n+1). Here n=28, so 28x29 = 812. Tip: Sum of even numbers is n(n+1).
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Question 73 of 100
What is the difference between the place value and face value of 9 in 50093?
ExplanationPlace value = 90, Face value = 9. Difference = 81. Tip: Place value depends on position, face value is the digit itself.
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Question 74 of 100
Which of the following is the smallest prime number?
Explanation2 is the smallest and the only even prime number. 1 is neither prime nor composite.
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Question 75 of 100
Which of the following is the smallest prime number?
Explanation2 is the smallest and the only even prime number. 1 is neither prime nor composite.
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Question 76 of 100
What is the sum of the first 39 natural numbers?
ExplanationFormula: n(n+1)/2. Here n=39, so 39x40/2 = 780. Tip: Always remember the sum of first n natural numbers formula.
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Question 77 of 100
What is the sum of the first 12 natural numbers?
ExplanationFormula: n(n+1)/2. Here n=12, so 12x13/2 = 78. Tip: Always remember the sum of first n natural numbers formula.
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Question 78 of 100
What is the difference between the place value and face value of 6 in 90655?
ExplanationPlace value = 600, Face value = 6. Difference = 594. Tip: Place value depends on position, face value is the digit itself.
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Question 79 of 100
What is the unit digit of 4^30?
ExplanationUnit digits follow a cyclicity of 4. Power 30 divided by 4 leaves remainder 2. Unit digit is 6. Tip: Memorize cyclicity of 2, 3, 7, 8.
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Question 80 of 100
What is the unit digit of 8^27?
ExplanationUnit digits follow a cyclicity of 4. Power 27 divided by 4 leaves remainder 3. Unit digit is 2. Tip: Memorize cyclicity of 2, 3, 7, 8.
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Question 81 of 100
Identify the nature of the number 21:
Explanation21 is a Composite number (3 x 7). Prime numbers have exactly two factors (1 and themselves). Composite numbers have more than two factors.
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Question 82 of 100
What is the sum of the first 15 odd numbers?
ExplanationFormula: n^2. Here n=15, so 15^2 = 225. Tip: Sum of first n odd numbers is always a perfect square.
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Question 83 of 100
What is the sum of the first 13 odd numbers?
ExplanationFormula: n^2. Here n=13, so 13^2 = 169. Tip: Sum of first n odd numbers is always a perfect square.
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Question 84 of 100
Which of the following is a rational number?
Explanation√36 is rational because it evaluates to a whole number. Irrational numbers cannot be expressed as p/q.
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Question 85 of 100
What is the unit digit of 7^41?
ExplanationUnit digits follow a cyclicity of 4. Power 41 divided by 4 leaves remainder 1. Unit digit is 7. Tip: Memorize cyclicity of 2, 3, 7, 8.
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Question 86 of 100
What is the sum of the first 33 natural numbers?
ExplanationFormula: n(n+1)/2. Here n=33, so 33x34/2 = 561. Tip: Always remember the sum of first n natural numbers formula.
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Question 87 of 100
Which of the following is the smallest prime number?
Explanation2 is the smallest and the only even prime number. 1 is neither prime nor composite.
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Question 88 of 100
What is the sum of the first 41 natural numbers?
ExplanationFormula: n(n+1)/2. Here n=41, so 41x42/2 = 861. Tip: Always remember the sum of first n natural numbers formula.
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Question 89 of 100
Which of the following is the smallest prime number?
Explanation2 is the smallest and the only even prime number. 1 is neither prime nor composite.
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Question 90 of 100
If a=21 and b=26, evaluate (a+b)².
Explanation(a+b)² = 2209. Tip: Use algebraic identities for faster calculations.
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Question 91 of 100
What is the unit digit of 7^25?
ExplanationUnit digits follow a cyclicity of 4. Power 25 divided by 4 leaves remainder 1. Unit digit is 7. Tip: Memorize cyclicity of 2, 3, 7, 8.
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Question 92 of 100
What is the cube of 9?
Explanation9 * 9 * 9 = 729. Tip: Memorize cubes up to 15 for competitive exams.
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Question 93 of 100
Which of the following is an irrational number?
Explanation√7 is irrational because its decimal expansion is non-terminating and non-recurring. √ of perfect squares are rational.
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Question 94 of 100
Which of the following is the smallest prime number?
Explanation2 is the smallest and the only even prime number. 1 is neither prime nor composite.
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Question 95 of 100
Identify the nature of the number 47:
Explanation47 is a Prime number. Prime numbers have exactly two factors (1 and themselves). Composite numbers have more than two factors.
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Question 96 of 100
What is the cube of 10?
Explanation10 * 10 * 10 = 1000. Tip: Memorize cubes up to 15 for competitive exams.
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Question 97 of 100
What is the difference between the place value and face value of 2 in 42945?
ExplanationPlace value = 2000, Face value = 2. Difference = 1998. Tip: Place value depends on position, face value is the digit itself.
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Question 98 of 100
What is the sum of the first 17 natural numbers?
ExplanationFormula: n(n+1)/2. Here n=17, so 17x18/2 = 153. Tip: Always remember the sum of first n natural numbers formula.
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Question 99 of 100
Which of the following is an irrational number?
Explanation√5 is irrational because its decimal expansion is non-terminating and non-recurring. √ of perfect squares are rational.
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Question 100 of 100
If a=27 and b=32, evaluate (a+b)².
Explanation(a+b)² = 3481. Tip: Use algebraic identities for faster calculations.
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