John takes 2 hours longer than Andrew to peel 400 pounds of apples. If together they can peel 400 pounds of apples in 7 hours, then how long would it take Andrew to peal the apples working alone? Please round your answer to three decimal places.

This is a basic algebra problem. The 400 apples is irrelevant to the problem.

J = John's time
A = Andrew's time
Here are the equations:

J + A = 7
A - 2 = J

2A - 2 = 7
2A=9
A=4.50 hours, thus this is your answer.

also J=2.50 hours.