1. | Which one of the following is not a prime number? | |||||||
Answer: Option D Explanation: 91 is divisible by 7. So, it is not a prime number. |
4. | What least number must be added to 1056, so that the sum is completely divisible by 23 ? | |||||||||
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5. | 1397 x 1397 = ? | |||||||||||||||||||||
Answer: Option A Explanation:
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6. | How many of the following numbers are divisible by 132 ? 264, 396, 462, 792, 968, 2178, 5184, 6336 |
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Answer: Option A Explanation:
132 = 4 x 3 x 11 So, if the number divisible by all the three number 4, 3 and 11, then the number is divisible by 132 also. 264 396 462 792 968 2178 5184 6336 Therefore the following numbers are divisible by 132 : 264, 396, 792 and 6336. Required number of number = 4. |
7. | (935421 x 625) = ? | |||||||||||||||||||
Answer: Option B Explanation:
= 584638125 |
8. | The largest 4 digit number exactly divisible by 88 is: | |||||||||
Answer: Option A Explanation:
Largest 4-digit number = 9999 88) 9999 (113 88 ---- 1199 88 ---- 319 264 --- 55 --- Required number = (9999 - 55) = 9944. |
9. | Which of the following is a prime number ? | |||||||
Answer: Option D Explanation: Clearly, 97 is a prime number. |
10. | What is the unit digit in {(6374)1793 x (625)317 x (341491)}? | |||||||
Answer: Option A Explanation:
Unit digit in (6374)1793 = Unit digit in (4)1793 = Unit digit in [(42)896 x 4] = Unit digit in (6 x 4) = 4 Unit digit in (625)317 = Unit digit in (5)317 = 5 Unit digit in (341)491 = Unit digit in (1)491 = 1 Required digit = Unit digit in (4 x 5 x 1) = 0. |