Here's a start
Making A = number of apples, O = number of oranges and P = number of pears
The unit prices are: .
Using at least one of each, get 100 fruits and 1 dollar ... without guessing.
There are 100 fruits: .
They cost 100 cents: .
Multiply  by 10: .
. . . . Subtract : .
. . . . And we have: . . .
Since is an integer, must be divisible by 8.
. . Hence: .
Substitute into  and solve for A.