Question

The credit remaining on a phone card (in dollars) is a linear function of the total calling time made with the card (in minutes). The remaining credit after 31 minutes of calls is $21.28, and the remaining credit after 69 minutes of calls is $16.72. What is the remaining credit after 76 minutes of calls?

Answer 1

Answer:

$15.88

Step-by-step explanation:

$\frac{(21.28 - 16.72)}{(69-31)}$

$4.56 / 38 min

$0.12 / 1 min

76 - 69 = 7 minutes

7 x .12 = .84

16.72 - .84 = 15.88