Question 1002869
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The Department of Education is holding their annual Brigada Eskwela to prepare and clean up the classrooms.
Kimberly can paint a chair in 45 minutes. Arthur can paint the same {{{highlight(cross(chairs))}}} <U>chair</U> in 30 minutes. 
If they work together, how long will it take them to paint six chairs.
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&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The solution and the answer in the post by @mananth are catastrophically wrong.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Trace attentively my solution below, &nbsp;and you will find, &nbsp;where @manant did his fatal error.



<pre>
The whole job is to paint 6 chairs (not one chair but six of them).


Kimberly can make this job in 30*6 = 180 minutes; hence, Kimberly makes 1/180 of the job per minute.

Arthur   can make this job in 45*6 = 270 minutes; hence, Kimberly makes 1/270 of the job per minute.


Working together, they make  

    {{{1/180}}} + {{{1/270}}} = {{{3/540}}} + {{{2/540}}} = {{{5/540}}} = {{{1/108}}}  of the job per minute.


Hence, they need 108 minutes, or 1 hour and 48 minutes to complete the job working together.      <U>ANSWER</U>
</pre>

At this point, the problem is solved completely and correctly.