Q1.

Find the L.C.M. of smallest composite number and smallest prime number

  • 1

  • 2

  • 3

  • 4

Solution:

4

Q2.

The H.C.F of two numbers a and b is 1 and their L.C.M. is -------

  • ab

  • a

  • b

  • 1

Solution:

ab

Q3.

Express number 17,017 as the product of primes.

  • 2 x 3 x 5 x 7

  • 7 x 13 x 11 x 17

  • 7 x 5 x 11

  • 11 x 17 x 2 x 19

Solution:

7 x 13 x 11 x 17

Q4.

Three bells sound at interval of 9, 12 and 15 minutes respectively. If they start ringing together, after what time bells will  ring together.

  • After 1 hr

  • After 3 hrs

  • After 4 hrs

  • After 150 minutes

Solution:

After 3 hrs

Q5.

Find the H.C.F of 1288 and 575.

  • 34

  • 15

  • 23

  • 63

Solution:

23

Q6.

The L.C.M. of two numbers 96 and 404 is 9696, find their H.C.F.

  • 4

  • 3

  • 2

  • 1

Solution:

4

Q7.

The L.C.M. and H.C.F of two numbers are 2175 and 145 respectively. If one number 725 find the other number.

  • 564

  • 435

  • 234

  • 865

Solution:

435

Q8.

Which statement is wrong ? 

(a). pie is an irrational number.

(b) Zero is the rational number.

(c) The sum of two prime numbers is always a prime number.

(d) The H.C.F. of two numbers is always a factor of their L.C.M.

  • C

  • A

  • B

  • D

Solution:

C

Q9.

Rational number 31/3125 terminates after _______ places of decimals.

  • 5

  • 4

  • 3

  • 2

Solution:

5

Q10.

Find the L.C.M. of 9/2,   3 and 21/2

  • 56

  • 63

  • 45

  • 72

Solution:

63