Answer:
a) Rental charge for 3 days = $ 66
b) Rental charge for 7 days = $ 131
Explanation:
a) Rent for 3 days.
Fixed rate = $ 45
Rate per day = $ 7
To find the rent for 3 days, multiply the unit rate by 3 and then add it to the fixed rate.
C(3) = 7*3 + 45
= 21 + 45
= $ 66
b) Rental charge for 7 days.
We have to find the rent for 3 days and then the rent for remaining 4 (7-3) days.
Rent for first 3 days = C(3)
= $ 66
The unit rate for the next 4 days is $5.
Rent for next 4 days = C(4)
= 5*4 + 45
= 20 + 45
= $ 65
Rent for 7 days = 66 + 65
= $ 131