Answer:
170 cartons ; 15 Grapefruits 
Explanation:
Given:- 
Total grapefruits : 4325
Bob sold : 1250 
Remaining is : 3075 (4325-1250)
How many gift cartons can Bob’s fill with the remaining grapefruits
Grapefruit per carton: 18 (given)
= 3075/18
= 170 cartons 
How many grapefruits will be left
= 3075 - 3060 
= 15 Grapefruits 
I hope my answer helps you.