LCM-HCF TNPSC Group 1 Questions

LCM-HCF MCQ Questions

1.

If LCM of "a" and "b" is a and LCM of "b" and "c" is b, then what is the LCM of "c" and "a".

Group 1 - 2019

A.

a

B.

b

C.

c

D.

abc

ANSWER :

A. a

2.

Find the LCM of 3(a-1), 2(a-1)2, (a2-1)

Group 4 - 2019

A.

(a+1)2(a+1)

B.

(a-1)2(a+1)

C.

6(a-1)(a+1)2

D.

6(a-1)2(a+1)

ANSWER :

D. 6(a-1)2(a+1)

3.

The GCD and LCM of two polynomials are x+1 and x4 - 1 respectively. If one of the polynomials is x2 + 1, find the other one.

Group 1 - 2019

A.

x3 - 1

B.

(x + 1)(x2 - 1)

C.

x2 + x -1

D.

x2 - x + 1

ANSWER :

B. (x + 1)(x2 - 1)

4.

Find the LCM of a3b4, ab5 and a2b7

Group 4 - 2016

A.

a7b3

B.

a3b7

C.

a2b5

D.

ab5

ANSWER :

B. a3b7

5.

Product of two positive number ,is 34560. The LCM is sixty times of its GCD. Then the difference of LCM and GCD is

Group 1 - 2017

A.

1416

B.

1424

C.

1460

D.

1464

ANSWER :

A. 1416

6.

The product of two numbers is 1600 and their H.C.F. is 5, the L.C.M. of the number is

Group 2 - 2018

A.

320

B.

1605

C.

1595

D.

8000

ANSWER :

A. 320