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The circle above has center at the origin and radius 3. How many order [#permalink]
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15 Dec 2017, 02:12
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4% (02:07) correct 96% (01:04) wrong based on 25 sessions
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Re: The circle above has center at the origin and radius 3. How many order [#permalink]
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15 Dec 2017, 20:41
Equation of circle > x^2 + y^2 = 9
We have to calculate the number of integer coordinates lying inside the circle.
Number of ordered pairs in 1st quadrant that do not lie along the origin = (1, 1), (2, 2), (1, 2), (2, 1) = 4
Number of ordered pairs in 4 quadrants not lying along the origin = 4 * 4 = 16
Number of ordered pairs lying along the origin = 9
Total = 16 + 9 = 25
Answer: E



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The circle above has center at the origin and radius 3. How many order [#permalink]
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24 Dec 2017, 15:40
Bunuel wrote: The circle above has center at the origin and radius 3. How many ordered pairs (x,y) satisfy the conditions that x and y are integers and (x,y) is inside the circle shown? (A) 9 (B) 13 (C) 16 (D) 20 (E) 25 Attachment: 20171215_1259_002.png I got Answer E, with the same method as VyshakBut OA says 9. (0,0)  (1,1)  (2,1) (0,1)  (1,2)  (2,2) (0,2)  (1,1) (2,1) (0,1) (1,2) (2,2) (0,2)(1,1)(2,1) (1,0) (1,2)(2,2) (2,0)  (1,1) (2,1) (1,0) (1,2) (2,2) (2,0) Bunuel , would you please check the OA?
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Re: The circle above has center at the origin and radius 3. How many order [#permalink]
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24 Dec 2017, 15:46
got answer E. Does ordered Pair (x,y) refer to any specific case? == Message from GMAT Club Team == This is not a quality discussion. It has been retired. If you would like to discuss this question please repost it in the respective forum. Thank you! To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative  Verbal Please note  we may remove posts that do not follow our posting guidelines. Thank you.
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Re: The circle above has center at the origin and radius 3. How many order
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