SOLUTION: If 8 workers can plough a 6 hectare field in 5 hours, how long will it take to plough a 9 hectare field with 5 workers?

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Question 1111794: If 8 workers can plough a 6 hectare field in 5 hours, how long will it take to plough a 9 hectare field with 5 workers?
Answer by ikleyn(52776) About Me  (Show Source):
You can put this solution on YOUR website!
.
The SIMPLEST and the MOST RELIABLE way to solve this problem is THIS:


In the first scenario,  the rate of work of one worker in one hour is equal to  6%2F%288%2A5%29  hectares%2Fhour.


Let x be how long will it take to plough the 9 hectare field with 5 workers, in hours.


In the second scenario,  the rate of work of one worker in one hour is equal to  9%2F%285%2Ax%29  hectares%2Fhour.



The rate is (assumed) the same, which gives you an equation (proportion)

6%2F%288%2A5%29 = 9%2F%285%2Ax%29.


Simplify by canceling common factors (which is "5" in this case):

6%2F8 = 9%2Fx.


Now solve for x, as you solve any proportion

x = %289%2A8%29%2F6 = 72%2F6 = 12.


Answer.  12 hours.

By doing in this way, you will NEVER make a mistake.

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To see other solved similar problem by the same method, look into the lesson
    - Rate of work problems
in this site.