<PRE><B>Question 35804</B>
If Brenda can clean the house in 2 hours and Kenny can clean the house in 3.5 hours, how long will it take them to clean the house if they work together?

Brenda Data:
   time = 2 hrs;  rate= (1/2)job/hr.
Kenny Data:
   time = (7/2) hrs; rate = (2/7)job/hr.
Together Data
   time =  x hrs;  rate = (1/x)job/hr.
EQUATION:
 rate + rate = rate
  1/2 + 2/7 = 1/x
Multiply both sides by 14x to get:
  7x + 4x = 14
      11x = 14
        x= 14/11 = 1.273 hrs = 1 hr 17 minutes

Cheers,
Stan H.</PRE>