Answer:
The cost price of each mango was $3
Explanation:
The man bought 500 mangoes, but 1/4 of them were rotten. There were 1/4*500 = 125 rotten mangoes, thus the number of mangoes he sold is
500 - 125 = 375 mangoes
Selling them at $3.36 each, he had revenue of
375*3.36=$1,260
That amount includes the 12% profit, that is, it's 112% of the cost price, thus the cost price of all mangoes is
1,260 / 112 * 100 = $1,125
The price of each mango was $1,125 / 375 = $3
The cost price of each mango was $3