Four - fifths of a number is greater than three - fourths of the number by 4. The number is

If, then n = ?

If 3(t - 3) = 5(2t + 1), then t = ?

The ages of A and B are in the ratio 5 : 7. Four years from now the ratio of their ages will be 3 : 4. The present age of B is

The base of an isosceles triangle is 6 cm and its perimeter is 16 cm. Length of each of the equal sides is