Please answer the following question by reasoning step-by-step.
Chang's Garden has two kinds of apples. Sweet ones and sour ones. He can sell the sweet ones for $.5 an apple. The sour ones sell for $.1 an apple. 75% of the apples he gets are sweet and the rest are sour. If he earns $40, how many apples did his trees give him?

100
25% of the apples are sour because 100 - 75 = 25.

The average price of an apple sold is $.

4 because.

75(.

5) +.

25(.

1) =.

4.

He got 100 apples because 40 /.

4 = 100.

.

The answer is 100