Final answer:
To calculate Maggie's phone bill for October when she uses 165 minutes, we determine the monthly base fee from her September bill and then add the cost of the October minutes to it. The total comes to $64.50.
Step-by-step explanation:
The subject of this question is to find the cost of Maggie's phone bill if she uses 165 minutes in October, given that Chichat wireless charges $0.30 per minute plus a monthly base fee. We have the information that in September, Maggie used 120 minutes and her bill was $51. To find the monthly base fee, we first calculate the cost of the minutes used in September: 120 minutes × $0.30/minute = $36. We then subtract this amount from the total bill to find the base fee: $51 - $36 = $15. This base fee is fixed and will be the same for October.
Now, to calculate the cost for October, we multiply the number of minutes used in October by the per-minute rate and then add the base fee: 165 minutes × $0.30/minute + $15 base fee. This gives us: 165 × 0.30 + 15 = $49.50 + $15 = $64.50. So, Maggie's bill for using 165 minutes in October will be $64.50.