Question 997824
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You can solve this problem even without using equations.


Let us suppose for a moment that all  50  coins are  10-cent. 

Then their value is  50*10 = $5.00.  It is less than  $5.30 in &nbsp $30 cents. 

It is clear that the difference is due to presence of  25-cent coins that we intently counted as  10-cent coins.

It is also clear that the number of these  25-cent coins is  {{{30/(25-10)}}} = {{{30/15}}} = 2  to compensate the difference. 

So,  the answer is:  there are  2  of  25-cent coins and  50-2 = 48  of  10-cent coins.


The solution is completed.


If you want to see more problems solved in this way,  look into these lessons 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/word/misc/Problem-on-two-wheels-and-three-wheels-bicycles-in-a-sale.lesson>Problem on two-wheel and three-wheel bicycles</A>, 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/word/misc/Problem-on-animals-at-a-farm.lesson>Problem on animals at a farm</A> &nbsp;and 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/word/misc/Problem-on-tablets-in-containers.lesson>Problem on pills in containers</A> 

in this site.


See also the lesson &nbsp;<A HREF=http://www.algebra.com/algebra/homework/word/coins/Solving-coin-problem-without-equations.lesson>Solving coin problems without using equations</A>.