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:

The income of A and B are in the ratio of 4:7. A and B saves Rs. 4000 and 5000 respectively. If the expenditure of A is equal to 60% of the expenditure of B. Then, find the difference between their incomes.

The ratio of the square of volume of two cylinders is a:b and the ratio of their radius is x:y, then what is the ratio of their heights?

Find the value of k in $$ {26\over 21}:{24\over 9 }::k :{14\over 13}$$

If a cuboid of dimensions 64cm×16cm×8cm is melted and recast into two equal cubes of same size. Then what will be the ratio of the surface are of cuboid to the total surface area of the two cubes?