HCF And LCM of ...

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?

The least multiple of 7, which leaves a remainder of 4, when divided by 6, 9, 15 and 18 is:

The least number, which when divided by 48, 60, 72, 108 and 140 leaves 38, 50, 62, 98 and 130 as remainders respectively, is:

The H.C.F. of two numbers is 11 and their L.C.M. is 7700. If one of the numbers is 275, then the other is:

A, B and C start at the same time in the same direction to run around a circular stadium. A completes a round in 252 seconds, B in 308 seconds and C in 198 seconds, all starting at the same point. After what time will they meet again at the starting point?

The L.C.M. of two numbers is 48. The numbers are in the ratio 2 : 3. Then sum of the number is:

The least number, which when divided by 12, 15, 20 and 54 leaves in each case a remainder of 8 is:

The product of two numbers is 4107. If the H.C.F. of these numbers is 37, then the greater number is:

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

The least number which should be added to 2497 so that the sum is exactly divisible by 5, 6, 4 and 3 is: