Question

A drum of oil is 3/4 full. When 15 litres of oil is drawn from it, it is 7/12 full. Find the total capacity of the drum

Answer 1

Let the total capacity of drum be x :

$\frac{3}{4}x - 15 = \frac{7}{12}x \\ \frac{3}{4}x - \frac{7}{12}x = 15 \\ \frac{9x - 7x}{12} = 15 \\ \frac{2x}{12} = 15 \\ \frac{1}{6}x = 15 \\ x = 90$
Ans should be 90