Question 367053
A does in 3 hours
so A does 1/3 of the job in 1 hour
..
B does in 6 hours
B can do 1/6 of the job in 1 hour.
..
together they can dp 1/3 + 1/6 of the job in 1 hour
= 3/6 
= 1/2 job in 1 hour
..
they will do the job in 2 hours
..
m.ananth@hotmail.ca