posted by Melissa on .
George pays a flat amount for the first 200 minutes plus so much for each additional minute on his cellular phone each month. Last month it cost him $33.78 for 244 minutes of use. The previous month it cost $38.94 for 287 minutes of use. What are the flat rate and per minute charge for his phone service?
if f is the flat rate, and m the per-minute rate,
f+287m = 38.94
f+244m = 33.78
notice that an extra 43 minutes cost an extra $5.16, or $.12/min. So, now we know that
f+287(.12) = 38.94, so
f = 4.5
so, the flat rate is $4.50