Deriving and changing the subject of formulae problem 28

At the market we bought 1 kg of prunes at 5 euros per kilogram, 5 kg of cottage cheese at 3 euros 83 cents per kilogram and 3 kg of cheese at 13 euros 54 cents per kilogram. At the cashier office we notice that we had a short fall of 11 euros 94 cents. Calculate how much the bill was and how much money we had in our wallet .