How do you figure out the percent decrease of 20 miles to 11 miles?

To find the percent decrease from 20 miles to 11 miles, subtract the new value (11 miles) from the original value (20 miles): 20 - 11 = 9 miles. Next, divide the decrease (9 miles) by the original value (20 miles): 9 ÷ 20 = 0.45. Finally, multiply by 100 to convert to a percentage: 0.45 × 100 = 45%. Thus, the percent decrease is 45%.