A driver of auto rickshaw makes a profit of 20% on every trip when he carries 3 passengers and the price of petrol is Rs. 30 a litre. Find the % profit for the same journey if he goes for 4 passengers per trip and the price of petrol reduces to Rs. 24 litres? (revenue per passenger is same)	Choose the correct choice from the following:
A) 20%  B) 33.33%  C) 100%  D) 65.66%  E) Data inadequate
Solution: Assume the cost price = 100 and selling price = 120.   Then, when price of petrol is reduced;   Cost price become 60 and selling price = 160;   Profit increased = 100%.   Answer: Option 100%
<result>C</result>
A driver of auto rickshaw makes a profit of 20% on every trip when he carries 3 passengers and the price of petrol is Rs. 30 a litre. Find the % profit for the same journey if he goes for 4 passengers per trip and the price of petrol reduces to Rs. 24 litres? (revenue per passenger is same)