The product of two co-prime numbers is $117$. Their $LCM$ should be:

Five bells begin to toll together and toll at intervals of $36, 45, 72, 81$ and $108$ seconds. After what interval of time will they keep on tolling together? (in $seconds$)

Find the least number which when decreased by $11$ is divisible by $14, 15, 21, 32$ and $60$.

Three different containers contain different quantities of a mixture of milk and water,measuring $403 \ kg$,$434 \ kg$,and $465 \ kg$. What is the largest measure that can measure all these quantities exactly? (in $kg$)

Let $N$ be the least six-digit number which,when divided by $4, 6, 10,$ and $15,$ leaves the same remainder of $2$ in each case. The sum of the digits in $N$ is:

The $L.C.M.$ and $G.C.D.$ of two numbers are $1530$ and $51,$ respectively. Find how many such pairs are possible?