Joann bought 8 books and a textbook.

Question

Joann bought 8 books and a textbook. She paid $200 to the cashier and received $20 change. If the textbook cost 7 times as much as each book, find the cost of the text book.

 

Please tell me the final answer to this question. 

Answer 1

Let X = cost of textbook

Let Y = cost of each book

 

Given that X = 7Y

 

X + 8Y = $180

7Y + 8Y = $180

15Y = $180

Y = $180 / 15 =  $12

 

8 books cost $12 each so 8 x $12 = $96

Textbook costs 7*$12 = $84

$84 + $96 = $180