you have to think that the original price multiplied by 0.75 (also known as 75%) gave the result of what he saves i.e 84 $. So we put up an equation with the original price multiplied by 75% which equals the 84 $ he saved on buying that item on sale
The order that the pitcher threw is F, C, F, F, C, C, F, F, F then the next five pitches are C, C, C, C, F, F, F, F, F assuming the pitcher maintains this order