If $1,000$ copies of a book of $25$ sheets require $50$ reams of paper,how much paper is required for $5,000$ copies of a book of $32$ sheets?

In a college,$150$ students of $MBA$ are enrolled. The ratio of boys to girls is $7:8$. There are three disciplines in the college: Marketing,$HR$,and Finance. In the Marketing discipline,there are $50\%$ girls of their total number and the boys are $40\%$ of their total number. In the $HR$ discipline,girls are $30\%$ of their total number while boys are $30\%$ of their total number. The Finance discipline has girls $20\%$ of their total number and the boys are $30\%$ of their total number. $7$ boys and $9$ girls are in $HR$ and Marketing both. $6$ boys and $7$ girls are in $HR$ and Finance both. $5$ boys and $8$ girls are in Marketing and Finance both. $2$ boys and $3$ girls are enrolled in all the three disciplines. By what percent is the number of boys in the Marketing discipline more than the number of girls in the $HR$ discipline?

What is the fourth proportional to $24, 120$ and $22$?

$A$ mixture of milk and water is kept in two separate containers. The ratio of milk to water in one container is $5:1$ and in the other container is $7:2$. In what ratio should the mixtures from these two containers be mixed so that the quantity of milk in the new mixture becomes $80\%$?

If $\frac{5a+3b}{2a-3b} = \frac{23}{5}$,then the value of $a:b$ is:

At present,Kavita is twice Sarita's age. $8 \ yr$ hence,the respective ratio between Kavita's and Sarita's ages will be $22:13$. What is Kavita's present age (in $yr$)?