The first game was 100*.8=<<100*.8=80>>80 hours of grinding

So it was 100-80=<<100-80=20>>20 hours of good gameplay

The expansion brought the time of good gameplay to 20+30=<<20+30=50>>50 hours

# Answer

50
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
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?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
50
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?
train