Answer:
The costs of the two plans would be equal with 200 minutes.
Explanation:
From the information given, you can write the following:
18+0.08x=10+0.12x, where x is the number of minutes of calls
Then, you can solve for x:
18-10=0.12x-0.08x
8=0.04x
x=8/0.04
x=200
According to this, the answer is that the costs of the two plans would be equal with 200 minutes.