Indian Institute of Foreign Trade 2019 Solved Paper

An E-rickshaw owner makes 24 trips a month with 4 passengers per trip. If his interest cost for purchase of E-rickshaw is ₹120/month, he earns 15 percent profit a month (Profit is the difference between revenue and cost). What will be the approximate percentage profit for the same month if the owner undertakes 20 trips a month with 5 passengers and his interest cost is reduced by 10 percent for the month ?
Assume:
(a) Total cost to be proportional to the interest cost.
(b) Revenue per passenger is the same in both cases.