Question

50% of all the cakes jenny baked were party cakes, 1/5 were fruit cakes and the remainder were sponge cakes. What percentage of cakes were sponge cakes?

Answer 1

So basically you want to find the total percentage of cakes that weren't sponge cakes first.

You already have the 50% of party cakes. For the 1/5 percent of fruit cakes, you can multiply it by 20/20, to get 20/100, and then just take the 20 to get 20% that were fruit cakes.

Now you can just add the percentages together.

50% + 20% = 70%

So now you know 70% weren't sponge cakes, out of 100%.

So here you can just subtract 70% from 100% to figure out the remaining part of 100%, which must be sponge cakes.

100% - 70% = 30%

So 30% of the cakes were sponge cakes.