Ming plays video games online. When he signed up with the game site, Ming got 200 points. Ming earns 20 more points for each hour that he plays. How many hours does Ming have to play to get to 500 points?
First, substract the total of points with the points he got from signing up, to find the points he got after playing points after playing = 500 - 200 points after playing = 300
Second, divide the points after playing by the number of points per hour, to find how long Ming played time = 300/20 time = 15