Find a fourth proportional to the numbers $60, 48, 30$.

In a family,the ratio of expenses to savings is $5:3$. If the expenses increase by $60\%$ and the income increases by $25\%$,the savings decrease by $Rs. 3500$. Find the increased income (in $Rs.$) of the family.

How many one-rupee coins,$50$-paise coins,and $25$-paise coins,whose numbers are in the ratio $5:7:12$,are together worth $₹ 115$?

In a school,there were $1554$ students and the ratio of the number of boys to girls was $4:3$. After a few days,$30$ girls joined the school but some boys left; as a result,the ratio of boys to girls became $7:6$. The number of boys who left the school is:

Find the $4^{th}$ proportional to $4, 16$ and $7$.

Salaries of Ravi and Sumit are in the ratio $2:3$. If the salary of each is increased by $₹4000$,the new ratio becomes $40:57$. What is Sumit's present salary (in $₹$)?