Question

Manuel noticed that his cellphone bill reflected a monthly fee of

$40 as well as a charge for $0.05 per minute on the phone.
Manuel lost his August phone bill, but knows how much he paid
for the month. Which of the following functions will help Manuel
determine the amount of minutes he was on the phone based on
the cost of the bill?

Answer 1

Answer: (total amount paid - $40) / 0.05

Explanation:

Given the following :

Monthly fee = $40

Additional fee = $0.05 per minute on phone

Given the the amount paid for the month is available, number of minutes he was on phone can be determined thus :

Total amount to be paid = monthly fee + additional fee

Additional fee = $0.05 × n

Where n = number of minutes on phone

Hence,

Total amount paid = $40 + $0.05n

If the amount paid is known, the number of minutes on phone can be calculated thus;

(Total amount paid - monthly fee) = $0.05n

n = (Total amount paid - monthly fee) / fee per minute on phone

(total amount paid - $40) / 0.05