Answer:
There are 13 grapefruits in the bag
Explanations:
Jillian placed all the grapefruits that weigh exactly 1/2 pounds into a bag. This means that:
Weight of 1 grapefruit = 1/2 pounds = 0.5 pounds
Let the number of grapefruits = n
The total weight of the bag (I.e all the grapefruits) = 6 1/2 = 6.5 pounds
Total weight of the bag = Number of grapefruits x Weight of 1 grapefruit
6.5 = n x 0.5
0.5n = 6.5
n = 6.5 / 0.5
n = 13
There are 13 grapefruits in the bag