Let us call x the weight of the grapefruit bag. Then we know that the weight of the grapefruit bag plus 1 5 /8 pounds plus 2 3 /16 pounds must equal 7 1/2 pounds.
Therefore, we have

The first step in simplifying the above is to convert each of the mixed numbers into improper fractions.



hence, our equation becomes

Adding the fractions on the left gives (to do this we first find their common denominators and then add them up)

subtracting 61/16 from both sides gives


As a mixed number, this is

Hence, the weight of the pag of grape