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 |
40 cents a day |
After 9 days |
80 cents a day |
Sam rented 2 books and was charged $18.40. How many days did he rent the books for?
$1 = 100¢
$18.40 = 18.40 x 100 = 1840¢
Amount that Sam paid for each book
= 1840 ÷ 2
= 920¢
Amount that Sam paid for each book for renting for the first 9 days
= 9 x 40
= 360¢
Additional amount that Sam paid for each book for renting for additional days
= 920 - 360
= 560¢
Number of additional days that Sam rented for each book
= 560 ÷ 80
= 7
Total number of days that Sam rented the books
= 9 + 7
= 16
Answer(s): 16