A fruit merchant bought some bananas. One fifth of them got rotten and were thrown away. He sold two fifth of the bananas at 15% profit and the remaining bananas at 10% profit. Find the overall loss or profit percent.

Profit 12%

⇒ Assume total 25 bananas are there and cost of each is Rs.10

Cost of 25 bananas = 25 × 10 = Rs.250

After throwing rotten bananas, remaining bananas = 25 × \(\frac{4}{5}\) = 20

Therefore, now the cost of 20 bananas = Rs.250

It means cost of each banana after throwing rotten bananas  = \(\frac{250}{20}\) = Rs.12.5

On 15% profit ⇒  no. of bananas = 20 × \(\frac{2}{5}\) = 8

S.P. of 8 bananas = (8 × 12.5) × 115% = Rs.115

On 10% profit ⇒  no. of bananas = 20 - 8 = 12

S.P. of 12 bananas = (12 × 12.5) × 110% = Rs.165

Total S.P. = 115 + 165 = 280

C.P. = 250

Profit = 280 - 250 = 30

Profit percent = \(\frac{30}{250}\) = 12%