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
OA is B
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Circle Problem
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Gmatss
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Not sure if my method is correct but, considering -2,-3 is the center and point 4,-3 is outside of the circle, and knowing that radius r is an integer, there are 5 spaces between -2,0 and 3,0 therefore raidus is 5.
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gmat009
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But how do you know that (3,0) lies on the circle. It may be possible that 3,0 is also outside circle .Gmatss wrote:Not sure if my method is correct but, considering -2,-3 is the center and point 4,-3 is outside of the circle, and knowing that radius r is an integer, there are 5 spaces between -2,0 and 3,0 therefore raidus is 5.
Centre of circle (-2, -3) and point (-2, 1): there are 4 spaces between them and lies inside circle
so radius>4
Centre of circle (-2, -3) and point (4, -3): there are 6 spaces between them and it lies outside circle
so radius < 6
4 < radius < 6
as radius is integer, radius = 5
so radius>4
Centre of circle (-2, -3) and point (4, -3): there are 6 spaces between them and it lies outside circle
so radius < 6
4 < radius < 6
as radius is integer, radius = 5
