Question

Tim had 187 dollars to spend on 9 books. After buying them he had 18 dollars. How much did each book cost?

Answer 1

Information

Tim had $187 dollars to spend.

Tim buys 9 books.

Tim has $18 dollars left after buying 9 books.

Steps

First, subtract the total amount of dollars Tim has to spend with his remaining balance after purchasing the books to find the total amount of cash spent on books.

$187 (total spending) - $18 (remaining balance) = $169 (spent on books)

Then, divide the amount of cash spent on books with the amount of books bought.

$169 (spent on books) ÷ 9 (books) = $18.77 (cost per book)

Quick note: You don't round up since this is dealing with cash. You can only round down, but leave to 2 decimal places (to the hundredths place) for a precise amount.

Conclusion

Tim spent $18.77 on each book.

Answer 2

Each book costed about $18.77

To do this problem do this:

9b = 187 - 18

This is because since you have 18 dollars left over subtract it from the total amount of money you had before.

9b = 169

Divide:

b = $18.77

To check you work multiply in 18.77, 9 times and add 18 dollars to it:

18.77(9) = 169

169 + 18 = 187