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A number n is said to be perfect if t...

A number `n` is said to be perfect if the sum of all its divisors (excluding `n` itself) is equal to `n` . An example of perfect number is (a) 6 (b) 9 (c) 15 (d) 21

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RS AGGARWAL-HCF AND LCM OF NUMBERS-All Questions
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  3. A number n is said to be perfect if the sum of all its divisors (ex...

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  6. The simplest reduction to the lowest terms of (116,690,151)/(427,863,8...

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  7. The highest common factor of 0 and 6 is (a) 0          (b) 3       ...

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  8. The H.C.F. of 2^2xx3^3xx5^5,\ \ 2^3xx3^2xx5^2xx7 and 2^4xx3^4xx5xx7...

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  9. The H.C.F. of 2^4xx3^2xx5^3xx7,\ \ 2^3xx3^3xx5^2xx7^2 and 3xx5xx7xx...

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  10. H.C.F. of 4xx27xx3125 ,\ \ 8xx9xx25xx7 & 16xx81xx5xx11xx49 is (a) 1...

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  11. Find the highest common factor of 36 and 84. (a) 4         (b) 6      ...

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  12. Even numbers are formed by taking at least two at a time from the numb...

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  13. The H.C.F. of 204, 1190 and 1445 is (a) 17       (b) 18       (c) 1...

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  14. Which of the following is a pair of co-primes? (a) (16, 62)     ...

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  16. The H.C.F. of 3556 and 3444 is (a) 23         (b) 25        (c) 26 ...

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  17. The L.C.M. of 2^3xx3^2xx5xx11 ,\ \ 2^4xx3^4xx5^2xx7 and 2^5xx3^3xx5...

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  18. Find the lowest common multiple of 24, 36 and 40. (a) 120    (b)...

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  19. The L.C.M. of 22, 54, 108, 135 and 198 is (a) 330     (b) 1980  ...

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  20. The L.C.M. of 148 and 185 is (a) 680      (b) 740    (c) 2960   ...

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