Final answer:
The costs of both plans are equal when there are 175 minutes.
Step-by-step explanation:
To find the number of minutes where the costs of both plans are equal, we need to set up an equation.
Let x be the number of minutes.
For Plan A:
Cost = $8.00 (monthly fee) + $0.18 (per long-distance minute)x
Cost of Plan A = $8.00 + $0.18x
For Plan B:
Cost = $15 (monthly fee) + $0.14 (per long-distance minute)x
Cost of Plan B = $15 + $0.14x
To find the number of minutes, we'll equate the costs of both plans:
$8.00 + $0.18x = $15 + $0.14x
Solve for x:
$0.18x - $0.14x = $15 - $8.00
$0.04x = $7.00
x = $7.00 / $0.04
x = 175
The costs of both plans are equal when there are 175 minutes.