Question 75065
I will give you one with the answer and you can try to use that example to make your own. 

It takes Sybil 6 hrs longer to paint a room than it takes Joanne. Working together, they can paint the room in 4 hours. How long would it take each working alone to paint the room? 

Rate of Sybil: 6 + x                  
Rate of Joanne: x 
Time together: 4 hrs               
Equation: 4/ (6+x) + 4/x 
Solution: Sybil: 12 hours, Joanne: 6 hours 
 

Good luck on your homework!