Cam bought some used books for $4.95. he paid $0.50 each for some books and $0.35 each for the others. he bought fewer than 8 books at each price. how many books did cam buy? show/type work

4.95 is how much he paid so you cannot go past that number
he bought 7 books at .35 cents, he spent 2.45 on that [ 7 x 0.35 ]
he bought 5 books at .50 cents , he spent 2.50 on that [ 5 x .50 ] 
2.45 plus 2.50 = 4.95 
7 plus 5 = 12
He bought 12 total books

Then why is the question on here if you know the answer

Ibelieve the answer is c