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 6 days |
40 cents a day |
After 6 days |
80 cents a day |
Tommy rented 3 books and was charged $21.60. How many days did he rent the books for?
$1 = 100¢
$21.60 = 21.60 x 100 = 2160¢
Amount that Tommy paid for each book
= 2160 ÷ 3
= 720¢
Amount that Tommy paid for each book for renting for the first 6 days
= 6 x 40
= 240¢
Additional amount that Tommy paid for each book for renting for additional days
= 720 - 240
= 480¢
Number of additional days that Tommy rented for each book
= 480 ÷ 80
= 6
Total number of days that Tommy rented the books
= 6 + 6
= 12
Answer(s): 12