Question 1160085
Big Ben digs 1/6 per day
John Stud digs 1/4 per day
Paul Bunyan digs 1/3 per day
1/6+1/4+1/3 = 3/4 per day
So it means they would get the job done in 4/3 = 1.33333, 1 day and 8 hours.