Question

a collection of 108 coins containing only quarters and nickels is worth $21.
coin collection
number of coins | value | total
--- | --- | ---
nickels | n | 0.05 | 0.05n
quarters | q | 0.25 | 0.25q
total | | |
which value could replace q on the chart?
108 − n
108
21 − n
21

Explanation:

Step1: Understand the total number of coins

We know that the total number of coins (nickels + quarters) is 108. Let the number of nickels be \( n \) and the number of quarters be \( q \). So, the equation for the total number of coins is \( n + q = 108 \).

Step2: Solve for \( q \)

To find \( q \) in terms of \( n \), we can rearrange the equation \( n + q = 108 \) by subtracting \( n \) from both sides. This gives us \( q = 108 - n \).

Answer:

\( 108 - n \)