Question 557511: A call to Tucson from a pay phone in Chicago cost 85 cents for the first minute and 27 cents for each additional minute or portion of a minute. If a student has $9.50 in change, how long can she talk?
Answer by TutorDelphia(193)   (Show Source):
You can put this solution on YOUR website! The hardest part of this question is the term each additional minute. If I make a call that's 10 minutes long, that'd be 1 minute plus 9 additional minutes. If my call was 15 minutes long, that'd be 1 minute plus 14 additional minutes. In general, its the flat rate minute, plus m-1 where m is the total number of minutes.
As an equation we get:
9.50=.85+.27(m-1)
distribute the .27
9.50=.85+.27m-.27
combine like terms
9.50=.58+.27m
subtract .58 from both sides
8.92=.27m
divide both sides by .27
And we get 33.03
So that'd by 33 minutes
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