Thread: Working backwards with percentages

There is one type of question to do with percentages that I just can't get my head around. Below is an example:

Staff at a computer game store get a discount of 21% on games. Bill bragged to his parents that he saved $102 last year. How much did Bill spend last year on games?

I have been given the answer as $383.71 but for the life of me I can't work out how they got it.

Originally Posted by MikeChch

There is one type of question to do with percentages that I just can't get my head around. Below is an example:

Staff at a computer game store get a discount of 21% on games. Bill bragged to his parents that he saved $102 last year. How much did Bill spend last year on games?

I have been given the answer as $383.71 but for the life of me I can't work out how they got it.

Hi Mike,

The amount that he saved is 21% of total.

The amount he spent was 79% of total.

1% of total is



79% of total is