Question 1091102
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<pre>
Let's translate your homework to equations.


First equation is 

F = {{{(1/3)*S}}},  or, which is the same,  3F = S.    (1)


Second equation is

F + 12 = {{{(1/2)*(S+12)}}},  which is the same as  2*(F+12) = S + 12.    (2)


At this moment you must make an effort and get understanding what is F+12 at the left side, and what is S+12 at the right side.
As soon as you understand it, you will easily solve ANY age word problem.


So, from the condition, you have this system of two equations

3F = S,              (1)   and
2*(F+12) = S + 12.   (2)


Simplify (2)

2F + 24 = S + 12

and substitute  3F instead of S into this equation, based on (1). You will get a single equation for F:

2F + 24 = 3F + 12  ====>  F = 24 - 12 = 12.
</pre>

<U>Answer</U>.  Fran is 12 years old.  Stan is 3*12 = 36 years old.



Solved.



There is a bunch of lessons on age word problems 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/word/age/Age-problems-and-their-solutions.lesson>Age problems and their solutions</A>

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/word/age/Fresh-formulation-of-a-traditional-age-problem.lesson>A fresh formulation of a traditional age problem</A>

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/word/age/Really-intricate-age-word-problem.lesson>Really intricate age word problem</A>

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

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/word/age/Age-problems-for-mental-solution.lesson>Age problems for mental solution</A> 

in this site.


Read them and become an expert in solving age 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 online textbook under the topic "<U>Age word problems</U>".