10 books * 9 shelves = 90 books
He already has more than that.
Now, if he wanted 10 books for each subject on each shelf, then he'd need to have 90 books for each subject.
So, he'd need to buy
90-72 = 18 History books
and so on for each subject
Then add up the results for all the books
Practice Dividing by 9
History : 72
Art: 81
Science: 54
Travel: 63
Fiction: 90
Biography: 45
Poetry: 27
Cooking: 36
1/Raul might put an equal number of each kind of book on 9 shelves. How many types of books will have an even number on each shelf?
Answer:
3 types of books..
Explain:
History: 72 divide 9= 8
&
Science: 54 divide 9=6
&
Cooking: 36 divide 9= 4
2/How many books would Raul have to buy if he wanted to have 10 books on each self, no matter what the subject?
Answer: don't understand
1 answer