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 5 days |
20 cents a day |
After 5 days |
60 cents a day |
Ethan rented 2 books and was charged $10.40. How many days did he rent the books for?
$1 = 100¢
$10.40 = 10.40 x 100 = 1040¢
Amount that Ethan paid for each book
= 1040 ÷ 2
= 520¢
Amount that Ethan paid for each book for renting for the first 5 days
= 5 x 20
= 100¢
Additional amount that Ethan paid for each book for renting for additional days
= 520 - 100
= 420¢
Number of additional days that Ethan rented for each book
= 420 ÷ 60
= 7
Total number of days that Ethan rented the books
= 5 + 7
= 12
Answer(s): 12