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 3 days |
60 cents a day |
After 3 days |
90 cents a day |
Mark rented 4 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 Mark paid for each book
= 2160 ÷ 4
= 540¢
Amount that Mark paid for each book for renting for the first 3 days
= 3 x 60
= 180¢
Additional amount that Mark paid for each book for renting for additional days
= 540 - 180
= 360¢
Number of additional days that Mark rented for each book
= 360 ÷ 90
= 4
Total number of days that Mark rented the books
= 3 + 4
= 7
Answer(s): 7