Answer :
There are 5 colors and one color is purple so what you can do is since there is 20 trays with one purple in each, your equation would be equivalent to 20 divided by 5 and the answer to that is 4. Your fraction is going to be 20•5 which is 100 then divide that by 4 and your fraction is 25/100 and to simplify that, the fraction is 1/4