Question 1089802
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A Cashier working alone serves 20 clients in 1 hour. A second Cashier serves the same number of clients in 40 minutes. 
What time will they need serving the 20 clients if they work both?
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<pre>
In this problem, let us call this work, serving 20 clients, as "one job".

Then the first cashier makes {{{1/60}}} of the job per minute. It is his rate of work.

The second cashier makes {{{1/40}}} of the job per minute. It is his rate of work.

When they work together, their combined rate of work is the sum of individual rates, i.e. {{{1/60 + 1/40}}} = {{{2/120 + 3/120}}} = {{{5/120}}} = {{{1/24}}}.

Thus we get that the two cashiers, working together, make {{{1/24}}} of the job per minute.

Now it is clear to you that it will take 24 minutes for both to serve 20 clients.


The problem is solved.
</pre>

It is a typical joint work problem.


There is a wide variety of similar solved joint-work problems with detailed explanations in this site. &nbsp;See the lessons

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/Rate-of-work-word-problems/Word-problems-WORKING-TOGETHER-by-Fractions.lesson>Using Fractions to solve word problems on joint work</A> 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/Rate-of-work-word-problems/Solving-more-complicated-word-problems-on-joint-work.lesson>Solving more complicated word problems on joint work</A> 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/Rate-of-work-word-problems/Selected-problems-from-the-archive-on-joint-work-word-problems.lesson>Selected joint-work word problems from the archive</A> 



Read them and get be trained in solving joint-work problems.


Also, &nbsp;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 lessons are the part of this textbook under the topic 
"<U>Rate of work and joint work problems</U>" &nbsp;of the section &nbsp;"<U>Word problems</U>".



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