Question 559244
you go to a game show and the prze at the end is a case full of $10 and $20
bills. The hosts tells you there are 400 bills in the case totaling $6,250. To
win you have to figure out how many 10 and 20 $ bills are in the case.
<pre>
This can be solved with or without using algebra.  I'll do it both ways:

1. Without algebra:

If all 400 bills were tens, there would be only $4000, which would be
$2250 short, so 225 of the bills must be worth an extra $10 to make it
worth $6250.  So there nust be 225 twenties and the rest (175) tens.  

2. With algebra:

Let x = the number of tens and  y = the number of twenties

               x +   y =  400  <-- the bill equation
             10x + 20y = 6250  <-- the money equation 

Solve that by substitution and get x=175 tens, y = 225 twenties.

Edwin</pre>