Bicycle wheel

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Bicycle wheel

by kamu » Mon Mar 09, 2009 3:10 pm
If a bicycle wheel has a radius of 14 inches, how many rotations will it make in a mile?

a. 5280/28pi

b. 63360/196pi

c. 5280/14pi

d. 15840/7pi

e. 63360/14pi

OA : D

:)
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by truplayer256 » Mon Mar 09, 2009 3:44 pm
Since the bicycle wheel has a radius of 14 inches, it'll have a diameter of 28 inches since the diameter is equal to 2 times the radius. To find out how many inches the wheel goes in 1 revolution, we find the circumference of the wheel. C=pi*d-->C of the wheel= pi*28=28pi inches
1 mile= 5280 feet
1 feet= 12 inches

Answer: (12*5280)/(28pi) since we want to find out how many revolutions it'll take for the wheel to travel one mile. The answer simplifies to 15840/7pi or D.