A works twice as fast as B. If both of them can together finish a piece of work in 12 hours, then B alone can do it in
Work done by A in one hour: 2x
Work done by B in one hour: x
Number of days taken by A and B to do the work together: 12 hours
Work done by A and B together in one hour:
= 2x + x
= 3x
X =
Here X is Work done by B in one hour
B alone will take 36 hours to complete the work.