50% of all the cakes jenny baked that jenny baked last week were party cakes 1/5 were fruit cakes and the remainder were sponge
what percentage were sponge?
30% of them were sponge cakes ( this is because 50% were party cakes and 20% were fruit cakes = 70% which left the sponge cakes, as they were the remainder, to be 30% of what she baked.)
