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 |
20 cents a day |
After 9 days |
70 cents a day |
Eric rented 3 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 Eric paid for each book
= 1380 ÷ 3
= 460¢
Amount that Eric paid for each book for renting for the first 9 days
= 9 x 20
= 180¢
Additional amount that Eric paid for each book for renting for additional days
= 460 - 180
= 280¢
Number of additional days that Eric rented for each book
= 280 ÷ 70
= 4
Total number of days that Eric rented the books
= 9 + 4
= 13
Answer(s): 13