You would turn 15% into a decimal. Which would be .15, and then do .15 times $29.99 which is $29.84. Then you would subtract the $29.99 minus the $29.84
It's 53. You have to put the numbers in order, then tick off a number from each end until you get to the middle. That is your number.
2,800
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A = pi times r^2
113.04 = pi times r^2
35.98 = r^2
5.99 = r or about 6
