document.write( "Question 755002: 3 painters took 15 hours to paint a house. How long would it take for 9painters to do the same \n" ); document.write( "

Algebra.Com's Answer #459450 by DrBeeee(684) $\"\"$ $\"About$

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Solving this problem can be done by calculating \"man-hours\" to do the job, namely, paint a house.
\n" ); document.write( "Let MH = number of man-hours to paint a house. From the problem statment,\"takes 3 painters (or \"men\"), 15 hours to paint a house, we get
\n" ); document.write( "(1) MH = 3*15 or
\n" ); document.write( "(2) MH = 45 painter-hours.
\n" ); document.write( "Now we want to know how long it will take 9 painters to do the same painting job. The answer is given by
\n" ); document.write( "(3) Number of hours = (Number of painter-hours required)/(number of painters) or
\n" ); document.write( "(4) Number of hours = MH/9 or
\n" ); document.write( "(5) Number of hours = 45/9 or
\n" ); document.write( "(6) Number of hours = 5
\n" ); document.write( "Answer: It will take 9 painters five hours to paint a house that takes 15 hours for 3 painters to paint.
\n" ); document.write( "Comment: The reason that this problem can be solved by simply using manhours is that we have the equivalent of 3 equal groups of 3 painters each. Beware other such problems require more analysis. Look in the archieve of problems of this type to learn more. \n" ); document.write( "

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