Question 1111794
.
<pre>
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/(8*5)}}}  {{{hectares/hour}}}.


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/(5*x)}}}  {{{hectares/hour}}}.



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

{{{6/(8*5)}}} = {{{9/(5*x)}}}.


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

{{{6/8}}} = {{{9/x}}}.


Now solve for x, as you solve any proportion

x = {{{(9*8)/6}}} = {{{72/6}}} = 12.


<U>Answer</U>.  12 hours.
</pre>

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


------------------
To see other solved similar problem by the same method, look into 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.