SOLUTION: eight mechanical experts can assemble 4 computers in 5 hours. how many mechanical experts will be needed to assemble 21 computers in 10 hours?

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Question 1082700: eight mechanical experts can assemble 4 computers in 5 hours. how many mechanical experts will be needed to assemble 21 computers in 10 hours?
Answer by ikleyn(52780) About Me  (Show Source):
You can put this solution on YOUR website!
.
Your proportion is

4%2F%288%2A5%29 = 21%2F%28x%2A10%29,

where x is the number under the question.


Solve for x.


4*x*10 = 21*8*5  ====>  x = %2821%2A8%2A5%29%2F%284%2A10%29 = 21.


Answer.  21 experts.


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
    - Rate of work problems
in this site.

Also, you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

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