Question 1098807

a stack of 20 coins contains only nickels and quarters and has a total value of $4 how many of each coin are in the stack
<pre>Let the number of nickels be N
Then number of quarters = 20 - N
We then get: .05N + .25(20 - N) = 4
.05N + 5 - .25N = 4
.05N - .25N = 4 - 5
- .2N = - 1
N, or number of nickels = {{{highlight_green(matrix(1,3, (- 1)/(- .2), "=", 5))}}}
Number of quarters: {{{highlight_green(matrix(1,3, 20 - 5, "=", 15))}}}