In order to find the original price, we need to divide by 4. This is because the price was reduced by 20%, it is 4/5 of the original price.
By dividing by 4, we can see that 90.40 is 22.60.
To find the original price, we add 22.60 (1/5 of the original price), to 90.40 (4/5 the original price) to find that $113 is the original price.
