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 with petrol. If the kerosene is now 15%, how much does the vessel hold?
1). 30 litres
2). 35 litres
3). 26 litres
4). 32 litres
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