Problems on H.C.F and L.C.M - General Questions

Find the greatest number that divides 83, 15, 51 leaving the same remainder in each case.

What is the least number which, when divided by 4, 9, 18, leaves a remainder 1 in each case?

Find the L.C.M. of 11, 35 and 6.

Find the L.C.M. of 5, 31 and 26.

The H.C.F. of two numbers is 7 and their L.C.M. is 588. If one of the numbers is 49, what is the other?