Question

Lashonda purchased a prepaid phone card for $20. Long distance calls cost 8 cents a minute using this card. Lashonda used her card onlyonce to make a long distance call. If the remaining credit on her card is $17.12, how many minutes did her call last?

Answer 1

We know that

• Lashonda purchased a prepaid phone card for $20.

,

• Long-distance calls cost 8 cents a minute.

,

• The remaining credit on her card is $17.12.

This problem can be expressed as

$20-0.08x=17.12$

Where x is the number of minutes.

We solve the equation for x

$\begin{gathered} -0.08x=17.12-20 \\ -0.08x=-2.88 \end{gathered}$

Then, we divide by -0.08 the equation

$\begin{gathered} \frac{-0.08x}{-0.08}=\frac{-2.88}{-0.08} \\ x=36 \end{gathered}$

Therefore, Lashonda's call last 36 minutes.