Answer: 24km
Explanation: radius is half of the diameter so we just multiply by 2 to get a diameter
Take the original price, multiply it by 20% (you have to move the decimal place two to the left, so it becomes .2), then subtract the answer from the original price.
39.99*.2= $7.998
39.99-7.998= $31.99
If you wanted to, you could also round the $7.998 to $8.00. Your answer would be the same.
