Answer:
3 11/16 pounds
Explanation:
The third item in the group had a weight that is the difference between the total and the sum of the two other items:
bag weight = (7 1/2) - ((1 5/8) +(2 3/16))
It can be convenient to use a common denominator of 16, so this is ...
bag weight = 7 8/16 - (1 10/16 + 2 3/16)
= 7 8/16 - (3 13/16)
= (7 -3) + (8/16 - 13/16)
= 4 - 5/16
= 3 11/16
The weight of the bag of grapefruit was 3 11/16 pounds.