Numbers Questions And Answers.
| Answer: Option D |
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| Explanation: |
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91 is divisible by 7. So, it is not a prime number. |
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| Answer: Option C |
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| Explanation: |
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(112 x 24) = 112 x (10/2)4= (112x104)/24 = 1120000/16 = 7000 |
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3. | It is being given that (232 + 1) is completely divisible by a whole number. Which of the following numbers is completely divisible by this number? |
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| A. | (216 + 1) |
| B. | (216 - 1) |
| C. | (7 x 223) |
| D. | (296 + 1) |
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| Answer: Option D |
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| Explanation: |
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Let 232 = x. Then, (232 + 1) = (x + 1).
Let (x + 1) be completely divisible by the natural number N. Then,
(296 + 1) = [(232)3 + 1] = (x3 + 1) = (x + 1)(x2 - x + 1), which is completely divisible by N, since (x + 1) is divisible by N. |
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4. | What least number must be added to 1056, so that the sum is completely divisible by 23? |
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| A. | 18 |
| B. | 20 |
| C. | 3 |
| D. | 2 |
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| Answer: Option D |
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| Explanation: |
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23) 1056 (45
92
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136
115
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21
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Required number = (23 - 21)
= 2. |
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| Answer: Option D |
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| Explanation: |
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1397 x 1397 |
= (1397)2 |
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= (1400 - 3)2 |
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= (1400)2 + (3)2 - (2 x 1400 x 3) |
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= 1960000 + 9 - 8400 |
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= 1960009 - 8400 |
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= 1951609. |
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Tutorial Link: |
Published by:Michael Daani