Question

Gillian purchased 25 books at the library book sale. Each hardcover book cost $1.50, and each paperback book cost $0.50. Gillian spent a total of $26.50. The book costs can be represented by the system of equations below.

h + p = 25
1.50h + 0.50p = 26.50
How many paperback books did Gillian buy?

Answer 1

25-14=11 and 26.5-21=5.5
11 paperback books

Answer 2

Number of books did Gillian buy is 11.

Explanation:

Given : Gillian purchased 25 books at the library book sale. Each hardcover book cost $1.50, and each paperback book cost $0.50. Gillian spent a total of $26.50.

To find : How many paperback books did Gillian buy?

Solution :

The book costs can be represented by the system of equations below.

`h+p= 25` ......(1)

`1.50 h + 0.50 p = 26.50` ......(2)

Solving the system of equations by substitution method

Substitute h=25-p from (1) into (2)

`1.50(25-p) + 0.50 p = 26.50`

`37.5-1.50p + 0.50 p = 26.50`

`p = 11`

Substitute back in equation (1),

`h+11= 25`

`h=14`

i.e. there are 11 paperback books and 14 hardcover books.

Therefore, Number of books did Gillian buy is 11.