Answer:
The equations
[tex]x + y = 80[/tex]
[tex]0.25x + 0.1y = 16.25[/tex]
The solution
55 dimes and 25 quarters
Step-by-step explanation:
Given
Let
[tex]x \to[/tex] quarters
[tex]y \to[/tex] dimes
[tex]Total = 80[/tex]
[tex]Worth = \$16.25[/tex]
Required
Set up a system of equation to calculate the number of each coin
The total coin of 80 implies that:
[tex]x + y = Total[/tex]
[tex]x + y = 80[/tex]
A dime = $0.1
A quarter = $0.25
So, the worth of the coin is:
[tex]0.25 * x + 0.1 * y = Worth[/tex]
[tex]0.25x + 0.1y = 16.25[/tex]
So, the equations are:
[tex]x + y = 80[/tex]
[tex]0.25x + 0.1y = 16.25[/tex]
Next, solve for x and y
Multiply the second equation by 4
[tex]0.25x + 0.1y = 16.25[/tex] by 4
[tex]x + 0.4y = 65[/tex]
Subtract from [tex]x + y = 80[/tex]
[tex]x- x + y - 0.4y = 80 - 65[/tex]
[tex]0.6y = 15[/tex]
Solve for y
[tex]y = 25[/tex]
We have:
[tex]x + y = 80[/tex]
[tex]x = 80 - y[/tex]
[tex]x = 80 - 25[/tex]
[tex]x = 55[/tex]
Hence, there are 55 dimes and 25 quarters