Answer:
16
Step-by-step explanation:
Convert 6 inches to 1/8" to make it easier.
1/8 just means there are 8 parts in a whole. 8*6=48.
There are forty-eight 1/8s in 6 inches. 48 divided by 3 (since you have 3/8 inch books) will give you your answer: 16
Hope that helps.
P.S. Please consider for brainliest if it did help. I need 2 more to rank up.