A vessel is full of a mixture of kerosene and petrol in which there is 20% kerosene. 5 litres are drawn off and then the vessel is filled w…

Let the total capacity of vessel be x litres

Kerosene in the vessel = 20x/100

Kerosene after 5 litres are drawn = 15x/100

Kerosene in 5 litres of mixture = (20 × 5)/100

⇒ 20x/100 – (20 × 5)/100 = 15x/100

⇒ 20x – 100 = 15x

⇒ 5x = 100

⇒ x = 20

Thus, Vessel holds 20 litres of kerosene