Find the least number which when divided separately by $15, 20, 36$ and $48$ leaves $3$ as remainder in each case.

Find the greatest number which will divide $25, 73$ and $97$ so as to leave the same remainder in each case.

$A$ merchant has $435$ litres,$493$ litres,and $551$ litres of three different kinds of milk. Find the least number of casks of equal size required to store all the milk without mixing.

The $LCM$ of $2^{2} \times 3^{2} \times 5 \times 11$,$2^{4} \times 3^{4} \times 5^{2} \times 7$,and $2^{5} \times 3^{3} \times 5^{2} \times 7^{2} \times 11$ is:

Three bells ring together and they will ring at intervals of $6$ seconds,$7$ seconds and $8$ seconds respectively. After what interval will they again ring together? (in seconds)

Three pieces of timber $42 \ m$,$49 \ m$,and $63 \ m$ long have to be divided into planks of the same length. What is the greatest possible length of each plank (in $m$)?