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# Can someone help me with this alegebra ?

Okay so I have to take an exam that covers basics of everything and I am having trouble with the alegebra part. Here is the question and I have the answer but can't figure out how to get to it:

If Sally can paint a house in 4 hours, and John can paint the same house in 6 hours, how long will it take for both of them to paint the house together?

THANK YOU!!!!!

Asked by Anonymous at 6:51 PM on May. 31, 2010 in Just for Fun

• 1/x= 1/4=1/6 1/x is the time it takes them to do it together 1/4 is the time it takes sally and 1/6 times it takes john. add them by finding the least common dinominator which is 3/12+2/12 which is 5/12...then take the recipericle. which is 12/5..it will take them together 2 and 2/5 hours ...which is 2 hours 24 minutes! hope i helped!

Answer by Mommy2JoshNJake at 7:14 PM on May. 31, 2010

• 5 hrs

Answer by Anonymous at 6:54 PM on May. 31, 2010

• 5?

Answer by Anonymous at 6:54 PM on May. 31, 2010

• 5 hours. That would be the "average time". 4+6=10; 10 divided by 2 is 5. The answer is 5 hours. I believe :)

Answer by SAHMinIL2 at 7:02 PM on May. 31, 2010

• The answer is 2 hrs and 24 minutes.

Answer by Anonymous at 7:02 PM on May. 31, 2010

• Sally can paint 1/4 of the house in 1 hour, John can paint 1/6 of the house in 1 hour. X will be the number of hours it takes to paint the house.
So you have x/4 +x/6 = 1 house
find the common denominator: 24 so you multiply x/4 by 6 and x/6 by 4
so now you have 6x/24 +4x/24 = 1
get x by itself: multiply both sides by 24 = 10x = 24
divide both sides by 10 to get x by itself x=24/10 or 12/5 = 2 hrs 24 min

Answer by Anonymous at 7:06 PM on May. 31, 2010

• dang i can't type...but the above person is correct too and it seems more organized lol

Answer by Mommy2JoshNJake at 7:15 PM on May. 31, 2010

• scroll down there's lots of examples at the bottom http://www.themathpage.com/alg/word-problems2-2.htm#upstream

Answer by Mommy2JoshNJake at 7:16 PM on May. 31, 2010

• NOT 5 hours! 2 hrs, 24 minutes is correct.

Answer by Pnukey at 7:46 PM on May. 31, 2010

• Thank you everyone! 2 hrs and 24 minutes is correct :) And thank you Mommy2JOshNJake for those word problems.

Answer by Anonymous at 8:42 PM on May. 31, 2010