A book rental shop rented out books and the rate of rental charges are shown in the table.
Number of days |
Rates |
After the first 9 days |
30 cents a day |
After 9 days |
60 cents a day |
Charlie rented 2 books and was charged $13.80. How many days did he rent the books for?
$1 = 100¢
$13.80 = 13.80 x 100 = 1380¢
Amount that Charlie paid for each book
= 1380 ÷ 2
= 690¢
Amount that Charlie paid for each book for renting for the first 9 days
= 9 x 30
= 270¢
Additional amount that Charlie paid for each book for renting for additional days
= 690 - 270
= 420¢
Number of additional days that Charlie rented for each book
= 420 ÷ 60
= 7
Total number of days that Charlie rented the books
= 9 + 7
= 16
Answer(s): 16