Given:
Chris has a collection of dimes and quarters worth $4.25.
To number of coins = 22
To find:
The number of quarters.
Solution:
Let x be the number of dimes and y be the number of quarters.
Total coins : [tex]x+y=22[/tex] ...(i)
we know that, 1 dime = $0.10 and 1 quarter = $0.25.
Total value : [tex]0.10x+0.25y=4.25[/tex] ...(ii)
Multiply equation (i) by 0.10 and subtract the result form (ii).
[tex]0.10x+0.25y-0.10(x+y)=4.25-0.10(22)[/tex]
[tex]0.10x+0.25y-0.10x-0.10y=4.25-2.20[/tex]
[tex]0.15y=2.05[/tex]
Divide both sides by 0.15.
[tex]y=\dfrac{2.05}{0.15}[/tex]
[tex]y=13.6667[/tex]
Number of quarter cannot be a decimal value.
[tex]y\approx 17[/tex]
Therefore, the number of quarter is about 17.
