radious

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Source: — Problem Solving |

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by hwiya320 » Tue Dec 09, 2008 8:08 pm
Ok,

7/16 inch is the radius, but 1 inch is 2 miles.
So we know that actual radius is (7/16)*2miles = 7/8 miles = radius

so the area of the circle

(7/8)^2*3.14

49/64 * 3.14

since it's estimate, let's round up.

50/65 is 0.8, close enough. round down 3.14 to the closest integer = 3
3x0.8 = 2.4

B

You need to round up or down to closest number without effecting the answer

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by ch0719 » Wed Dec 10, 2008 12:35 am
i see, this way is easier. i did the other way (calculated the area in inch and then try to convert to miles, but forgot that in this case it is miles^2)

just curious, is it possible to solve this problem by calculating the area in inch first and then make it into square miles