Answer:
There are 7 quarters and 9 nickels.
Explanation:
Let the number of quarters = x
Let the number of nickels = y
There are a total of 16 coins, therefore:
[tex]\begin{gathered} x+y=16 \\ \implies x=16-y \end{gathered}[/tex]
• 1 Quarter = $0.25
,
• 1 Nickel =$0.05
Since the total value in the cup is $2.20, we have that:
[tex]0.25x+0.05y=2.20[/tex]
We substitute x in the first equation into the second one.
[tex]\begin{gathered} 0.25x+0.05y=2.20 \\ 0.25(16-y)+0.05y=2.20 \\ 4-0.25y+0.05y=2.20 \\ -0.25y+0.05y=2.20-4 \\ -0.2y=-1.8 \\ y=-\frac{1.8}{-0.2} \\ y=9 \end{gathered}[/tex]
Recall: x=16-y
Therefore:
[tex]\begin{gathered} x=16-9 \\ x=7 \end{gathered}[/tex]
There are 7 quarters and 9 nickels.