The length, breadth and height of a room are in the ratio 7:3:1. If the breadth and height are doubled while the length is halved, then by what percent the total area of the 4 walls of the room will be increased?

A sum of Rs. 110 is in the form of Rs. 2, Rs. 1 and 50 paise coins in the ratio of 1 : 2 : 3, respectively. How many 50 paise coins are there?

The diameter of two cones is the same. If the ratio of their slant height is 5 : 4, then find the ratio of their areas. 

The ratio of ages of Jai and Joy is 5:2. The sum of their ages is 63. After 9 years what will be the ratio of their ages?

If N:38∷ 3:57, Find N.

Six years ago, the ratio of the ages of the two persons P and Q was 3:2. Four years hence the ratio of their ages will be 8:7. What is P’s age?

If three numbers are in the ratio 2:3:5 and the twice their sum is 100. Find the square of the largest of the three numbers.

If a=2b/3, b=2c/3, and c=2d/3, then find the ratio of b and d: