Jonathan can play three hours of video games for every 5 hours he studies. This means that for every hour he studies, he is allows to play 3/5 of hours of videogame:

So, for every hour spent studying, Jonathan can play 3/5 = 0.6 hours, while Lucas can play 30 minutes, which is half an hour, which is 0.5.
So, every hour spent studying rewards Jonathan with more time for videogames than Lucas.