Question 677581
Let m be the minutes of long-distance calls in a month to make plan A the better deal.
Therefore, charges for Plan A = $15 + 0.08m
and charges for Plan B = $3 + 0.12m
By condition,
3 + .12m > 15 + .08m
.12m - .08m > 15 - 3
.04m > 12
{{{m > 12/.04}}}
{{{m > (12 * 100)/4}}}
m > 300
Therefore more than 300 minutes of long-distance call will make Plan A better deal.