Option B
There are 30 quarters
<em><u>Solution:</u></em>
Let "x" be the number of quarters
Let "y" be the number of dimes
We know that,
Value of 1 quarter = 0.25 dollars
Value of 1 dime = 0.10 dollar
<em><u>The counter said there were 180 total coins </u></em>
Therefore,
number of quarters + number of dimes = 180
x + y = 180
y = 180 - x ------- eqn 1
<em><u>The coins were worth $ 22.50. Therefore, frame a equation as:</u></em>
number of quarters x Value of 1 quarter + number of dimes x Value of 1 dime = 22.50
0.25x + 0.1y = 22.50 -------- eqn 2
<em><u>Let us solve eqn 1 and eqn 2</u></em>
<em><u>Substitute eqn 1 in eqn 2</u></em>
0.25x + 0.1(180 - x) = 22.50
0.25x + 18 - 0.1x = 22.50
0.25x - 0.1x = 22.50 - 18
0.15x = 4.5
x = 30
Thus there are 30 quarters