<PRE><B>Question 224526</B>
OK
Let x=amount of time it takes them working together to wash a car
Then, together, they wash at the rate of 1/x car per min
Sue washes at the rate of 1/48 car per min
John washes at the rate of 1/16 car per min

So, together, they wash at the rate of 1/48 + 1/16 car per min

So our equation to solve is:
1/48 + 1/16 = 1/x  Hint: multiply each term by 48x

I bet you can take it from here :)

Hope this helps---ptaylor</PRE>