Jo makes 170 minutes call. There are 150 free ones 170 - 150 = 20 20 minutes are "what Jo has to pay" Jo sends 182 texts. There are 150 free ones 182 - 150 = 32 32 texts are "what Jo has to pay"
Monthly charge = 16p, 13p for each extra minute, 15p for each extra text. 13(20) = 260p 15(32) = 480p
480p + 260p + 16 = 740p + 16
740p + 16 is your answer (if p = pounds, add 16 to it, i'm not sure what p stands for though. If it is cents, divide 100 from 740 and take out the p, then add total to 16 to get answer.)
Well, the answer would bee 1/10 for a simple reason: the 3 in 7.315 is in the tenth's spot while the 3 in 893.5 is in the ones. a one spot different that can be proven with logic.
