<PRE><B>Question 191592</B>
Making Change. Christina makes a $9.25 purchase
at a bookstore in Reno with a $20 bill. The store has no
bills and gives her the change in quarters and fifty-cent
pieces. There are 30 coins in all. How many of each kind
are there?
--------------------
q = # of quarters
h = # of half dollars
Her change is $11.75
---------------
q + h = 30   (30 coins)
25q + 50h = 1175 (the total money)
q = 30-h  (from the 1st eqn)
Sub that into the 2nd eqn
25(30-h) + 50h = 1175
750 - 25h + 50h = 1175
25h = 425
h = 17
q = 13
You can do the check
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