Answer: $4.5 left.
Explanation:
You have 30 quarters, and find 20% more. To convert percentages to decimals for calculations, simply move the decimal two spaces to the left.
20% is 20. ---> 2.0 ---> .20
30 * 0.2 = 6. Now add 6 (found) to 30 (original) to get the total.
30+6 = 36 total quarters.
You spend 50% of the quarters, 36 * 0.5 = 18.
This means you have 18 quarters left (or you spent 18).
18 quarters, each quarter is worth 0.25 dollars, so multiply the number left by how much each is worth.
18 * 0.25 = $4.5.