Question 1082700
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<pre>
Your proportion is

{{{4/(8*5)}}} = {{{21/(x*10)}}},

where x is the number under the question.


Solve for x.


4*x*10 = 21*8*5  ====>  x = {{{(21*8*5)/(4*10)}}} = 21.


<U>Answer</U>.  21 experts.
</pre>


Notice that each side of the proportion express the work rate (productivity) in the units "computer per man-hour".


Making such proportion is the easiest way to solve the problem.



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It is typical joint work problem. See the lesson

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/Rate-of-work-word-problems/Rate-of-work-problem.lesson>Rate of work problems</A> 

in this site.


Also, you have this free of charge online textbook in ALGEBRA-I in this site

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson>ALGEBRA-I - YOUR ONLINE TEXTBOOK</A>.


The referred lesson is the part of this textbook under the topic "<U>Rate of work and joint work problems</U>" of the section "<U>Word problems</U>".