Mathematics - HCF and LCM

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Question - 1

252 can be expressed as a product of primes as:

  • A \(2 \times 2\times3\times3\times7\)
  • B \(2\times2\times2\times3\times7\)
  • C \(3\times3\times3\times3\times7\)
  • D \(2\times3\times3\times3\times7\)

Question - 2

Which of the following has most number of divisors?

  • A 99
  • B 101
  • C 176
  • D 182

Question - 3

A number \(\pi\)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

Question - 4

\(1095\over1168\) when expressed in simplest form is:

  • A \(13\over16\)
  • B \(15\over16\)
  • C \(17\over26\)
  • D \(25\over26\)

Question - 5

Reduce \(128352\over238368\) to its lowest terms.

  • A \(3\over4\)
  • B \(5\over13\)
  • C \(7\over13\)
  • D \(9\over13\)

Question - 6

The H.C.F of \(2^{2}\times3^{3}\times5^{2}\),\(2^{3}\times3^{2}\times5^{2}\times7\) and \(2^{4}\times3^{4}\times5\times7^{2}\times11\) is :

  • A \(2^{2}\times3^{2}\times5\)
  • B \(2^{2}\times3^{2}\times5\times7\times11\)
  • C \(2^{4}\times3^{4}\times5^{5}\)
  • D \(2^{4}\times3^{4}\times5^{5}\times7\times11\)

Question - 7

The H.C.F of \(2^{4}\times3^{2}\times5^{3}\times7\),\(2^{3}\times3^{3}\times5^{2}\times7^{2} \) and \(3\times5\times7\times11\) is :

  • A 105
  • B 1155
  • C 2310
  • D 27720

Question - 8

H.C.F of \(4\times27\times3125\),\(8\times9\times25\times7\) & \(16\times81\times5\times11\times49\) is :

  • A 180
  • B 360
  • C 540
  • D 1260

Question - 9

Find the highest common factor of 36 and 84 .

  • A 4
  • B 6
  • C 12
  • D 18

Question - 10

The H.C.F of 204,1190 and 1445 is :

  • A 17
  • B 18
  • C 19
  • D 21