Question 271610
We can set up the following equation:
(1/30)+(1/45)+(1/90)=1/x Multiply 90x to get:
3x+2x+x=90 Combine like terms:
6x=90 Divide each side by 6 to get:
x=15
There we go. 15 minutes. Working together pays off.
RJ 
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