The $LCM$ of two prime numbers $x$ and $y$ $(x > y)$ is $161$. The value of $3y - x$ is

In a school,$391$ boys and $323$ girls have been divided into the largest possible equal classes,so that each class of boys numbers the same as each class of girls. What is the number of classes?

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?

The $HCF$ and $LCM$ of two numbers are $21$ and $84$ respectively. If the ratio of the two numbers is $1:4$,then the larger of the two numbers is

Find the smallest number of five digits exactly divisible by $12, 16, 18$ and $27$.

If the $L.C.M.$ and $H.C.F.$ of two expressions are $(x^{2}+6x+8)(x+1)$ and $(x+1)$ respectively, and one of the expressions is $x^{2}+3x+2$, find the other.