SOLUTION: Barbara has some dimes and quarters. If she has 19 coins worth a total of $2.50, how many of each type of coin does she have?

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Question 1129064: Barbara has some dimes and quarters. If she has
19 coins worth a total of $2.50, how many of each type of coin does she have?
Answer by ikleyn(52772) About Me  (Show Source):
You can put this solution on YOUR website!
.
Let assume for a minute that all 19 coins are dimes.


Then their sum would ne 190 cents, which is 250-190 = 60 cents less than the given total.


So, we need to replace some dimes in our hypothetical collection of 19 dimes by quarters.


At each exchange we increase the total in the hypothetical collection by 25-10 = 25 cents.


So, we should make 4 = 60%2F15 exchanges to compensate this 60 cents difference.


It gives you the


Answer.  19-4 = 15 dimes and 4 quarters.

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This solution might seem as joking trick to you.  But actually it is totally legal solution.

And it is an easy way to solve such problems MENTALLY in your head.


For other methods to solve such problems see the lesson
    - Three methods for solving standard (typical) coin word problems
in this site.