AMCAT Maths LCM and HCF Questions & Answers

1. If the sum of two numbers is 55 and the H.C.F. and L.C.M of these numbers are 5 and 120
respectively, then the sum of the reciprocals of the numbers is equal to:

A): 55/601
B): 601/55
C): 11/120
D): 120/11

Correct Answer : C

2. The L.C.M. of two numbers is 4800 and their G.C.M. is 160. If one of the numbers is 480, then the other number is:

A): 1600
B): 1800
C): 2200
D): 2600

Correct Answer : A

3. The L.C.M. of two numbers is 140. If their ratio is 2:5, then the numbers are:

A): 28,70
B): 28,7
C): 8,70
D): 8,40

Correct Answer :A

4. The product of two numbers is 16200. If their LCM is 216, find their HCF:

A): 75
B): 70
C): 80
D): Data inconsistent

Correct Answer : A

5. M and N are two distinct natural numbers. HCF and LCM of M and N are K and L respectively. A is also a natural number, which of the following relations is not possible:
A): K*L=A
B): K*A=L
C): L*A=K
D): None of these

Correct Answer : C

6. The ratio of two numbers is 3:4 and their HCF is 4.Their LCM is:
A): 12
B): 16
C): 24
D): 48
Answer 5:

Correct Answer : D

7. What will be obtained if 8 is subtracted from the HCF of 168, 189, and 231:

A): 15
B): 10
C): 21
D): None of these

Correct Answer : D

8. The product of two numbers is 2028 and their H.C.F. is 13. The number of such pairs is:

A): 1
B): 2
C): 3
D): 4

Correct Answer : D