C=15 is the correct answer.
9514 1404 393
Answer:
400 minutes
Step-by-step explanation:
The cost of the first plan is ...
A = 14 + 0.15m . . . . . . . . where m is the number of minutes used
The cost of the second plan is ...
B = 30 + 0.11m
The costs will be equal when ...
14 +0.15m = 30 +0.11m
0.04m = 16 . . . . . . . . . . . . . subtract 14+0.11m from both sides
m = 400 . . . . . . . . . . . . . . . divide by 0.04
The plans will have the same cost for 400 minutes of calls.
Answer:
240 minutes
Step-by-step explanation:
60 minutes = 1 hour
4 hours = 60*4 = 240 minutes