John dances 3+5=<<3+5=8>>8 hours
John's total time is 3+5+1=<<3+5+1=9>>9 hours
James dances 9/3=<<9/3=3>>3 hours longer than that
So James dances 9+3=<<9+3=12>>12 hours
So the total dancing time is 8+12=<<8+12=20>>20 hours
#### 20