How many boxes of apples are there in the fifth question on page 13 of the third grade mathematics volume II?
300 kilograms of apples.
Suppose the apple is X and the orange is Y. From the meaning of the question, X=2Y, X- 180=Y-30, X- 150=Y, Y= 150. If X=2Y is brought into the question and X=300, then the apples are 300 Jin and the oranges are 600 Jin.