Question 1171182
.
<pre>

(a)  The entire job is  18*3 = 54 worker-days.


     12 workers will complete it in  {{{54/12}}} = 4 {{{1/2}}} days = 4.5 days.   <U>ANSWER</U>   <<<---===  edited after the notice by @greenestamps

                                                                    Thanks to @greenestamps (!)




(b)  If the number of worker decreases, the time to complete the job increases.    <U>ANSWER</U>
</pre>

Solved.


--------------


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.


You will find there many similar and more complicated problems on joint work with solutions and explanations.


Learn the subject from there.



Happy learning (!)