Question

When making a long distance call from a certain pay phone, the first three minutes of a call cost $2.20. After that, each additional minute or portion of a minute of that call costs $0.15. Use an inequality to find the maximum number of minutes one can call long distance for $3.85.

a. At most 2 minutes
b. At most 14 minutes
c. At most 26 minutes
d. At most 11 minutes

Answer 1

Answer: B

Explanation:

3.85 - 2.20 = 1.65

1.65/.15 = 11

11 + 2.20 = 13.20 minutes

Which is under 14

Answer 2

d. At most 11 minutes

Explanation:

The fixed price at 3 minutes is 2.20. We have the variable x that represents how many minutes beyond that first 3 minutes at .15 a minute. And we can only spend $3.85 to make this call. The inequality then looks like this:

.15x + 2.20 ≤ 3.85

.15x represents fifteen cents a minute for x number of minutes,

the 2.20 is what you pay for the first three minutes,

and since we only have 3.85 to spend on the call, we use the less than or equal to sign; it's ok to spend 3.85 and it's also ok to spend less than that, but since we only have 3.85, it's definitely not ok to spend more than that. Solving the inequality:

.15x ≤ 1.65 so

x ≤ 11