Question

A phone company offers two monthly plans. Plan A costs $11 plus an additional $0.16 for each minute of calls. Plan B costs $29 plus an additional $0.14 for each minute of calls.

For what amount of calling do the two plans cost the same?

What is the cost when the two plans cost the same?

Answer 1

The plans will cost the same when the amount you have to pay for talking for "x" minutes on Plan A is the same has what you have to pay for talking for the same number of "x" minutes when using Plan B.

$$ Plan A = $$ Plan B

To find the charge on each plan we add the base rate to the per minute call rate for each.

Plan A = $27 + $0.11x

Plan B = $13 + $0.15x

Let's drop the $ sign for now and get rid of the decimal point by multiplying by 100.

2700 + 11x = 1300 + 15x

Subtracting 11x and 1300 from both sides:

4x = 1400

x = 350 min.

Using this result the plans both cost $65.50 for 350 min of talk time.

Explanation:

boom :)