Answer:
567 minutes each month.
Explanation:
Let x be the number of minutes of talk time used each month.
The cost for talk time beyond 500 minutes is $0.08 * (x - 500)
The cost for email is $27.70 * 0.3 = $8.31
The total monthly cost is $27.70 + $0.08 * (x - 500) + $8.31 = $35.99
The total cost for 9 months is $35.99 * 9 = $323.91
So we can set up the equation:
$27.70 + $0.08 * (x - 500) + $8.31 * 9 = $367.29
Solving for x, we get:
x = 567
So the number of minutes of talk time used each month is 567 minutes.