A shopkeeper has certain number of apples of which 10% are found to be rotten. He sells 85% of the remaining good apples and still has 405 good apples. How many apples did he originally have?

3000

15% of Good apples = 405

Total number of Good people =  \(\frac{20}{3}\) × 405 = 2700

Number of Good apples = 90% of  Total number of apples

Total number of apples =  \(\frac{10}{9}\) × 2700

= 3000