Question 356244
sally - 4hours
she does 1/4 of the job in 1 hour
..
Ben = 6 hours
he does 1/6 of the job in 1 hour
..
together they do 1/4 + 1/6 of the job in 1 hour
=(3+2)/12
=5/12 of the job in 1 hour
so they will together take 12/5 hours
=2.4 hours
....
m.ananth@hotmail.ca