Question

A drum of kerosene oil is 3by 4 full .when 15 litres of oil is drawn from it, it is 7by12 full . find the total capacity of drum

Answer 1

Let total capacity be x

Initially drum is 3x/4 full
Then 15 litres is removed
i.e (3x/4 - 15)

Finally drum js 7x/12 full

So,
3x/4 - 15 = 7x/12
Multiplying by 12 on both sides

9x - 180 = 7x
2x= 180
x = 90 litres