From a tank of petrol , which contains 200 liters of petrol, the seller replaces each time with kerosene when he sells 40 liters of petrol(or mixture). Everytime he sells out only 40 liters of petrol (pure or impure). After replacing the petrol with kerosene 4th time, the total amount of kerosene in the mixture is

Correct Answer: 118.08L

The amount of petrol left after 4 operations = 200×1-402004=81.92 

 

Hence the amount of kerosene = 200 - 81.92 = 118.08 liters