Radius of the Circle.

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Radius of the Circle.

by jayanti » Fri Aug 12, 2011 2:07 am
In the xy-plane, the point (-2, -3) is the center of a circle. The point (-2, 1) lies inside the circle and the point (4, -3) lies outside the circle. If the radius r of the circle is an integer, then r =
A. 6
B. 5
C. 4
D. 3
E. 2
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by krishnasty » Fri Aug 12, 2011 2:43 am
IMO B

If observed carefully, the point inside the circle( lets say A) is 3+1 = 4 units from the centre on y axis. Hence, the radius has to be greater than 4. Omiting out options D,E and C

THe point which lies outside the circle is 2+4 = 6 units away from centre on X-azis. hence, omiting out option A.

The option left is B
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by pemdas » Fri Aug 12, 2011 2:44 am
4<r<6, hence r=5
jayanti wrote:In the xy-plane, the point (-2, -3) is the center of a circle. The point (-2, 1) lies inside the circle and the point (4, -3) lies outside the circle. If the radius r of the circle is an integer, then r =
A. 6
B. 5
C. 4
D. 3
E. 2
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