Question 6835
sally paints a house in 4 hours --> in 1 hour she paints 1/4 of house
john paints a house in 6 hourse --> in 1 hour, he paints 1/6 of house.


So, in 1 hour together they will paint 1/4+1/6 of the house ie


they paint 5/12 of house in 1 hour. So divide by 5/12, and we get:
(5/12)/(5/12) in 1/(5/12) hours

--> they paint 1 whole house in 12/5 hours.


this is 2.4 hours, ie 2 hours 24 minutes.


jon.