Lex was chatting with his friends Thomas and mike. He was wondering how much it will cost him to take a taxi from his house to work, a total of 12 km. Thomas and mike both recently took a taxi from the same company that charges an initial fee and also a constant rate per km travelled. Neither can remember how much the rates were but they have the receipt. Thomas traveled 10km and paid %24.50. Mike travelled 15km and paid $35. How much will Lex pay to travel a distance of 12km?