Question

Kala purchased a prepaid phone card for $30.00. Calls cost 5 cents a minute using this card. The credit, C (in dollars), left on the card after it is used for x minutes of calls is given by the following C= 30.00-0.05x How much credit is left after Kala uses it for 20 minutes of calls?

Answer 1

$29.00 credit left on the card.

Explanation:

The credit, C, left on the card after Kala uses it for 20 minutes of calls can be calculated by substituting x = 20 into the equation C = 30.00 - 0.05x.

Let’s calculate:

C=30.00−0.05×20

This simplifies to:

C=30.00−1.00=$29.00

So, after 20 minutes of calls, Kala has $29.00 credit left on the card.

Answer 2

Answer: 2999 cents

Step-by-step explanation:

You have 30 USD which is 3000 cents ( 1 USD = 100 cents )

so your formula must be 3000-0.05*20 = 2999 cents