A book and a magazine costs $7.20. Judy bought 2 books and 4 magazines for $20.20. How much is the cost of 5 books.

Answer 1

Let's denote the cost of a book as B and the cost of a magazine as M.

From the given information, we can write two equations:

1) 2B + 4M = $20.20
2) B + M = $7.20

From equation 2, we can rewrite M in terms of B as M = $7.20 - B

Substitute M in terms of B into equation 1:

2B + 4($7.20 - B) = $20.20
2B + $28.80 - 4B = $20.20
-$2B = -$8.60
B = $4.30

Now we have found the cost of one book to be $4.30. To find the cost of 5 books, we simply multiply the cost of one book by 5:

5 books * $4.30/book = $21.50

Therefore, the cost of 5 books is $21.50.