Subtract 3/5 from 1 2/3.
Re-write the problem as "subtract 3/5 from 5/3."
5 3
--- - -----
3 5
Note that the LCD here is (3)(5) = 15.
Multiply 5/3 by (15/15) and also multiply 3/5 by (15/15). Your result should be
25 9
------- - -----
15 15
Subtracting, we get 16/15. This is the answer. The green peppers weighed 16/15 lb, or 1 1/15 lb, more than did the other peppers.