Question

an empty fuel tank of a car was lled with a type petrol. when the tank was half empty, it was lled with b type petrol. again when the tank was half-empty, it was lled with a type petrol. when the tank was half-empty again, it was lled with b type petrol. what is the percentage of a type petrol at present in the tank?

Answer 1

Let the capacity of the tank be 100 litres.

Initially: A type petrol = 100 litres.

After first operation:

A type petrol = [(100/2)] = 50 litres;  

B type petrol = 50 litres.

After second operation:

A type petrol = [(50/2 + 50)] = 75 litres;  

B type petrol = [(50/2)] = 25 litres.

After third operation:

A type petrol = [(75/2)] = 37.5 litres;

B type petrol = [(25/2 + 50)] = 62.5 litres.

Required percentage = 37.5%.