Question 355145
1/5+1/x=1/2
1/x=1/2-1/5
1/x=(5-2)/2*5
1/x=3/10
3x=10
x=10/3
x=3.33 hours for Andy to paint the barn working alone.
Proof:
1/5+1/3.33=1/2
(3.33+5)/(5*3.33)16.67=1/2
8.33/16.67=1/2
1/2=1/2