Answer: 133 minutes
Explanation:
Hi, to answer this question we have to write an equation for the cost of each company:
The cost is equal to the fixed fee (40) plus the product of the cost per minute talking on the phone (0.25) and the minutes spent talking in the phone in the month (m)
40 + 0.25 m
The cost is equal to the fixed fee (60) plus the product of the cost per minute talking on the phone (0.10) and the minutes spent talking on the phone in the month (m)
60+ 0.10m
- Since both costs must be equal:
40 + 0.25 m = 60+ 0.10m
Solving for m:
0.25m-0.10m = 60-40
0.15m = 20
m = 20/0.15
m= 133.34 minutes = 133 minutes (rounded)