You can
put this solution on YOUR website!simpliy, you are finding the average of the two when they both paint a house...
in order to find the average, you add 4 hrs with 6 hrs (which gives you 10 hrs),
then divide by how many numbers you added, (which in this case is 2)...
10/2=5
Both of them painting a house together only takes about 5 hours according to the problem you had given me...
You can
put this solution on YOUR website!Sally takes 4 hours to paint the house so she paints 1/4 of the house per hour.
John takes 6 hours so he paints 1/6 of the house per hour.
In one hour they paint 1/4 + 1/6 of the house.

To paint the whole house will take 12/5 of an hour
ie 2 hours and 24 minutes.