HELP!!!
Marta bakes 3 types of cake: chocolate, fruit, and sponge. The recipe for each cake includes flour and sugar and she uses 3.3kg of flour and 3.1kg of sugar in total.
Each chocolate cake uses 225 g of flour and 300g of sugar
Each fruit cake uses 320g of flour and 250g of sugar
Each sponge cake uses 400 g of flour and 325g of sugar
Marta sells chocolate cakes for $12, fruit cakes for $10, and sponge cakes for $8 and makes a total of $114
How many of each cake does she make?
(Answer in the back of the book: 4 chocolate, 5 fruit, 2 sponge cakes)