A fruit seller buys some oranges and by selling 40% of them he realizes the cost price of all the oranges. As the oranges being to grow over-ripe, he reduces the price and sells 80% of the remaining oranges at half the previous rate of profit. The rest of the oranges being rotten are thrown away. The overall percentage of profit is:

Explanation:-

Let fruit seller buys 100 oranges for Rs. 100.
On selling of 40% of the oranges he realizes his cost price i.e. He sells 40 oranges for Rs. 100.
Profit on 40 Oranges = 100 - 40 = Rs. 60.
% profit on 40 oranges = ^{(60 *100)}/₄₀ = 150%.
Now, he sells 80% of 60 oranges on half of the previous profit i.e. 48 oranges, he sells at 75% of profit.
So, SP of 48 oranges = 48 + 75% of 48 = 84.

12 was rotten so he threw away.

Total SP = 100 + 84 = Rs. 184.
Profit = 184 - 100 = 84.
%Profit = 84%.