Question 391142
if sally paints a house in 4 hours and john can paint it in 6 hours, how long will it take them to paint the house together. the answer is 2 hours and 24 min but i dont understand how they got it. please break down the problem . thank you
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Sally 4 hours -------- 1 job
1/4 of the job in 1 hour.
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John 6 hours ------------1 job
1/6 of the job in 1 hour
..
Together they do {{{1/4 + 1/6}}} of the job in 1 hour
={{{5/12}}} of the job in 1 hour.
So they will together do the job in {{{12/5}}}hours
= 2.4 hours
= 2 hours +0.4*60minutes
=2hours + 24 minutes
2 hours 24 minutes
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m.ananth@hotmail.ca