



 
Hi Roger, I also got 231 cubic inches. (I used a radius of 8.175 inches. Is that what you have?) The volume V of a cylinder is given by V = π r^{2} h where r is the radius and h is the height. You have a volume of 231 cubic inches and a height of 20 miles and you are looking for the radius. First convert 20 miles to inches, There are 5280 feet in a mile and 12 inches in a foot so 20 miles is 20 × 5280 × 12 inches. Thus
Hence
and
Harley  


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