Revolutions- Wheel

[Guest]

A wheel is d feet in diameter.

Determine the following:

A- Distance in one complete revolution.

B- Number of revolutions in a mile.


My solution:

pi * d = circumference

5280/pi * d or 1681.53/ d = revolutions (formulas given as solution).

Let d = .5 ft.

pi = 3.14

A - 3.14 * .5 = 1.57 ft.

B- 5280/ 3.14 * .5 = 840.76 = 841 revolutions in mile.

1681.53 / .5 = 3,363.06 = 3,363 revolutions in mile.

Where did I make the miscalculation(s) ?

[Guest]

The formula is
5280/(pi * d)
(note the brackets)
or
1681.53/d
so the answer is 3,363.

Hope this helped,

R. Baber.