Question 330450
<br>Lucy has acollection of 300 coins of 5 cents and ten cents coins. If the total value of her collection is 45.00, how many of each kind are there? <br>

This problem as written has no "real" answer.<br>

If you had 300 10 cent coins with no 5 cent coins, that would only add up to 30 dollars.  But the question says that the total value of the 300 coins is 45.00.<br>

This is an impossible real world situation.  Please check the question and submit again.  :)<br>

But if we go through the motions, this is what we are looking at:<br>

Let x=number of 5 cent coins
Let y=number of 10 cent coins<br>

Thus<br>

x+y=300 given
.05*x+.10*y=45.00 given<br>

We need to solve this system of equations!<br>

Multiply the bottom equation by 20.  Then we have:<br>

x+y=300
x+2y=900<br>

Then subtract the bottom equation from the top.<br>

-y=-600 or y=600<br>

Then x+y=300 or x-600=300 and x=-300<br>

The only answer to this system of equations would be x=-300, y=600<br>

Unfortunately, in real world terms, it is not possible to have a negative amount of coins!