Seema,Meena,and Reena start jogging around a circular stadium and complete one round in $54 \text{ seconds}$,$42 \text{ seconds}$,and $63 \text{ seconds}$ respectively. Approximately after how many minutes will they meet again at the starting point?

$HCF$ of $4 \times 27 \times 3125$,$8 \times 9 \times 25 \times 7$ and $16 \times 81 \times 5 \times 11 \times 49$ is

Amit,Sucheta,and Neeti start running around a circular track and complete one round in $18 \text{ seconds}$,$24 \text{ seconds}$,and $32 \text{ seconds}$,respectively. In how many seconds will the three meet again at the starting point if they all started running at the same time?

What is the least number of cut pieces of equal length that can be cut out of two lengths $10\, m\, 857\, mm$ and $15\, m\, 87\, mm$?

Find the greatest number of four digits which must be added to $5231$ so that the final number becomes exactly divisible by $12, 15, 27, 32$ and $40$.

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