a2zinterviews

1.	The smallest number which when diminished by 7, is divisible by 12, 16, 18, 21 and 28 is
	A.  1008
	B.  1015
	C.  1022
	D.  1032

Solution

Required numbers =(L.C.M of 12,16,18,21,28) + 7 ‹=›1008 + 7 = 1015.

2.	The H.C.F of two numbers is 11 and their L.C.M is 7700. If one of the numbers is 275, then the other is
	A.  279
	B.  283
	C.  308
	D.  318

Solution

Other number = (11×7700 / 275) = 308.

3.	The H.C.F. of two numbers is 23 and the other two factors of their L.C.M. are 13 and 14. The larger of the two numbers is
	A.  276
	B.  299
	C.  312
	D.  322

Solution

Clearly, the numbers are (23 x 13) and (23 x 14). Larger number = (23 x 14) = 322.

4.	Which of the following is a pair of co–primes?
	A.  (16, 62)
	B.  (18, 25)
	C.  (21, 35)
	D.  (23, 92)

Solution

H.C.F. of 18 and 25 is 1. So, they are co-primes.

5.	The ratio of two numbers is 3 : 4 and their H.C.F. is 4. Their L.C.M. is
	A.  12
	B.  16
	C.  24
	D.  48

Solution

Let the numbers be 3x and 4x. Then, their H.C.F. = x. So, x = 4. So, the numbers are 12 and 16. L.C.M. of 12 and 16 = 48.