.Lindsay can paint 1/x of a certain room in 20 minutes. What fraction of the same room can Joseph paint in 20 minutes if the two of them can paint the room in an hour, working together at their respective rates?
1/3x
3x/x-3
x-3/3x
x/x-3
x-3/x












Work done for 20 mins = 1/x ; so for 60 mins it is ---> 3/x or (3 times)
Given Lindsay + Joseph paint the room in -- 1hr
If Lindsay did 3/x of the total work then remaining work = 1-3/x or x-3/3
For 20 mins Joseph did (x-3/3) * 20/60 = x-3/3x