Howdy there! ;) The answer to your question is 0.75. I got the answer because you divide 15 and 20( 15/20) So simplify if you want to. 15/5=3 20/5=4 equals 3/4 there are 4 25's in a hundred 25,50,75,100 so since 3/4 is three then it would be 0.75.
Hope I helped! :D