Question 278148
c=0.25(t-500)+47.95 
92.70<.25(t-500)+47.95<123.20
92.70<.25t-125+47.95<123.20
92.70<.25t-77.05<123.20
92.70+77.05<.25t<123.20+77.05
169.75<.25t<200.25
169.75/.25<t<200.25/.25
679<t<801 [679 & 801 are the total minutes within the price range of 
%92.70 & $123.95.]
679-500=179 minutes is the minimum min. over the 500.
801-500=301 minutes is the max min. over the 500.