LCM and HCF

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

2. The HCF of two numbers is 12 and their difference is also 12. The numbers are
66,78 94,106 70,82 84,96

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

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

5.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?
4 10 15 16


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

7.LCM of 87 and 145 is
870 1305 435 1740

8.The traffic lights at three different road crossing change after every 48 sec; 72 sec; and 108 sec., respectively. If they all change simultaneously at 8:20:00 hrs, then they will again change simultaneously at
8:27:12 Hrs 8:27:24 Hrs 8:27:36 Hrs 8:27:48 Hrs

9.The greatest number by which if 1657 and 2037 are divided the remainders will be 6 and 5 respectively is
127 235 260 305

10. The HCF and LCM of two numbers are 44 and 264 respectively. If the first number is divisible by 3, then the first number is
264 132 Both a and b 33