Answer:
20 minutes
Explanation:
The monthly charge(C) of the customer is represented by:
C = 40 + 0.3m
where m is the number of minutes used by the customer. We need to find how many minutes did the customer use if the bill is $46. For this we substitute 46 in place of C and find the corresponding value of m.
So,
46 = 40 + 0.3m
46 - 40 = 0.3m
6 = 0.3m
6/0.3 = m
m = 20 minutes
This means the person used 20 minutes which makes the bill equal to $ 46