If $P: Q = 8: 15$ and $Q: R = 3: 2$,then find $P: Q: R$.

The incomes of $A, B$ and $C$ are in the ratio $7: 9: 12$ and their expenditures are in the ratio $8: 9: 15$. If $A$ saves one-fourth of his income,then the ratio of the savings of $A, B$ and $C$ is:

The fourth proportional to $0.2, 0.12$ and $0.3$ is

Hitesh is $40$ years old and Ronnie is $60$ years old. How many years ago was the ratio of their ages $3:5$?

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 $₹$)?

The sum of the present ages of a father and his son is $90$ years. $10$ years ago,the ratio of their ages was $5:2$. The present age of the father is (in years):