20.50 into a fraction is 41/2. Since 20 is already a whole number, there is no need to convert it. Since .50 is a decimal, I have to convert it to a fraction, which is 1/2. I end up with the mixed number 20 1/2. Since I need to convert it to a fraction, I have to simplify it. 20 1/2 written as a fraction greater than 1 is 41/2.
Hope this helped !!