Find the least number of square tiles required to pave the ceiling of a hall $17 \, m \, 55 \, cm$ long and $8 \, m \, 10 \, cm$ broad.

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 of five digits which when divided by $12, 16, 21, 36$ and $40$ leaves a remainder of $8$ in each case.

The product of two $2$-digit numbers is $2160$ and their $H.C.F.$ is $12$. The numbers are:

The maximum number of students among whom $1001$ pens and $910$ pencils can be distributed in such a way that each student gets the same number of pens and the same number of pencils is:

Three electronic devices make a beep after every $48\, seconds$,$72\, seconds$,and $108\, seconds$ respectively. They beeped together at $10:00\, a.m.$ The time when they will next make a beep together at the earliest is: