Question 839329
It took 9 days for 2 people to paint a fence, which means that each day 1/9 of the fence was painted.  Since 2 people painted the fence, each of them painted 1/18 of the fence each day.


We are then asked how many days it would take 3 people to paint a fence.  Using the fact that each person (out of 2) painted 1/18 of the fence each day, to find out how long it would take 3 people to paint the fence, we will multiply 1/18 by 3, which is 1/6.  This means that 1/6 of a fence gets painted each day when 3 people are painting it, which also means that it will take 6 days for the fence to be painted.


ANSWER:  6 days