Question 1084206
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<pre>
Since Terri and Candace can mow the lawn in 18 min, they mow {{{1/18}}} of the lawn area per minute working together.


Since Candace can mow the lawn in 30 min, he (or she ?) mows {{{1/30}}} of the lawn area per minute working alone.


Hence, Terri working alone can mow {{{1/18-1/30}}} = {{{5/90-3/90}}} = {{{2/90}}} = {{{1/45}}} of the lawn area per minute.


Thus it will take 45 minutes for Terri to complete the job working alone.
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Solved.  4 (four) lines to get the solution with mental calculations, without solving equations.



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It is a typical joint work problem.


There is a wide variety of similar solved joint-work problems with detailed explanations in this site. 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, 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>" of the section "<U>Word problems</U>".