James gets bored with his game so decides to play a different one.  That game promises 100 hours of gameplay but 80% of that is boring grinding.  However, the expansion does add another 30 hours of enjoyable gameplay.  How much enjoyable gameplay does James get?
How many hours of grinding was the first game? ** The first game was 100*.8=<<100*.8=80>>80 hours of grinding
How many hours of good gameplay was the first game? ** So it was 100-80=<<100-80=20>>20 hours of good gameplay
How many hours of good gameplay did the expansion bring? ** The expansion brought the time of good gameplay to 20+30=<<20+30=50>>50 hours
#### 50