Question

Lisa purchased a prepaid phone card for $30. Long distance calls cost 13 cents a minute using this card. Lisa used her card only once to make a long distance call. If the remaining credit on her card is $26.49, how many minutes did her call last?

Answer 1

27minutes

Explanation:

Firstly, let us calculate the amount spent

amount spent=30-26.49

amount spent=3.51

the expression for the total amount spent is given as

y=c-mx

let us convert 13cents to dollar= $0.13 extra charge per minute

we can see that x is the number of minutes

therefore

26.49=30-0.13x

26.49-30=-0.13x

-3.51=-0.13x

x=3.51/0.13

x=27 minutes

the last call was 27minutes