SOLUTION: A cellular phone company offers a contract for which the cost C, in dollars, of t minutes of telephoning is given by C=0.25(t-600)+73.95, where it is assumed that t ≥ 600 min
Question 548676: A cellular phone company offers a contract for which the cost C, in dollars, of t minutes of telephoning is given by C=0.25(t-600)+73.95, where it is assumed that t ≥ 600 minutes. What times will keep costs between $123.95 and $143.95?
For the cost to be between $123.95 and $143.95, the telephoning time must be between ? minutes and ? minutes. Answer by Sarpi(32) (Show Source):
You can put this solution on YOUR website! C = 0.25(t - 600)+ 73.95 solve for t? if cost is between $123.95 and $143.95 that is
Therefore:
Hence,the telephone time must be between 800mins and 880mins in order for the cost to be between $123.95 and $143.95
