Question

Customers of a phone company can choose between two service plans for long distance calls. The first plan has a $8 monthly fee and charges an additional $0.12 for each minute of calls. The second plan has a $18 monthly fee and charges an additional $0.7 for each minute of calls. For how many minutes of calls will the costs of the two plans be equal?

Answer 1

200 minutes

Explanation:

Let us assume the number of minutes be x

Now the two equations are

$8 + 0.12x = 0

And, $18 + 0.7x = 0

In the case when the cost of the two plans is equal

So

$8 + 0.12x = $18 + 0.7x

$8 - $18 = 0.7x - 0.12x

-$10 = -0.05x

x = 200 minutes