HCF and LCM MCQ Questions
11-Find the LCM of 12(x-1)3 and 15(x-1)(x+2)2
(A) 60(x-1)3(x+2)2
(B) 60(x-1)
(C) 3(x-1)
(D) 3(x-1)3(x+2)2
12-The L.C.M. of 22, 54, 108, 135 and 198 is
(A) 300
(B) 1890
(C) 5940
(D) 10560
13- If P is a prime number, then the L.C.M. of P and P + 1 is
(A) P2 + 1
(B) P(P+1)/2
(C) (P+1)2
(D) P(P+1)
14- The ratio of two numbers is 3:4 and their H.C.F is 4. Find their L.C.M.
(A) 12
(B) 16
(C) 24
(D) 48
15-The HCF and LCM of two numbers m and n are 6 and 210 respectively. If m + n =72 the 1/m + 1/n is equal to
(A) 1/35
(B) 2/35
(C) 3/35
(D) 4/35
16-Three numbers are in the ratio 3:4:5 and their LCM is 2400. Find the HCF.
(A) 40
(B) 70
(C) 110
(D) 180
17-Three numbers are in the ratio of 2:3:4 an their HCF is 10. The numbers are
(A) 10, 20, 30
(B) 20, 30, 40
(C) 30, 20, 40
(D) 40, 20, 30
18-The LCM of two numbers is 2310 and their HCF is 30. If one number is 210, the other number is
(A) 330
(B) 1370
(C) 2010
(D) 16570
19-The HCF of 6/7, 5/14 and 10/21 is
(A) 5/7
(B) 1/21
(C) 1/42
(D) 30/7
20-LCM of x3 – a3 and (x – a)2 is
(A) (x3 – a3) (x – a)
(B) (x3 – a3) (x – a)2
(C) (x3 – a3) (x + a)
(D) (x – a)2 (x2 + ax + a2)
ANSWERS:
11-(A), 12-(C), 13-(D), 14-(D), 15-(B), 16-(A), 17-(B), 18-(A), 19-(C), 20-(D)