# LCM and HCF 1/1

1. LCM of $\displaystyle\frac{2}{7},\displaystyle\frac{3}{{14}}{\rm{ and }}\displaystyle\frac{5}{3}{\rm{ is}}$
a. 45
b. 35
c. 30
d. 25

2. About the number of pairs which have 16 as their HCF and 136 as their LCM, the conclusion can be
a. only one such pair exists
b. only two such pairs exist
c. many such pairs exist
d. no such pair exists

3. The HCF of two numbers is 12 and their difference is also 12. The numbers are
a. 66, 78
b. 94, 106
c. 70, 82
d. 84, 96

4. The HCF of two numbers is 16 and their LCM is 160. If one of the numbers is 32, then the other number is
a. 48
b. 80
c. 96
d. 112

5. HCF of three numbers is 12. If they are in the ratio 1:2:3, then the numbers are
a. 12,24,36
b. 10,20,30
c. 5,10,15
d. 4,8,12

6. Six bells commence tolling together and toll at intervals of 2,4,6,8,10 and 12 seconds respectively. In 30 minutes, how many times do they toll together?
a. 4
b. 10
c. 15
d. 16

7. The largest natural number which exactly divides the product of any four consecutive natural numbers is :
a. 6
b. 12
c. 24
d. 120