Integers that lie on a circle

[ramyaravindran]

How can I solve this?. Don't have a OA.
A circle has radius of 5.How many points of the form (x,y) lie in the x-y plane where x and y are both integers that lie on the circle.

[kstv]

x²+y²=25 eq of the circle
(x,y) should be (+-3,+-4) and (+-4,+-3)
2 points in each quadrant
8 points

[yeahdisk]

Why not 5,0 0,5 0,-5 -5,0 ?

[kstv]

Yes it should be 12 points. Thanks.

[yeahdisk]

cool - I wasn't sure if 0 counted as an integer on GMAT tests (but - after seeing your reply - I'm guessing it does)

[kstv]

Heh I am more prone to careless mistakes then is good.
See the post below which is yet unanswered. Though sanju09's answer I suspect is right and 0 is an integer.

https://www.beatthegmat.com/square-coord ... tml#235646

the purpose of posting this link is because similar kind of concepts may be tested in differnt forms.

Tut Tut should have learrned from that mistake I made in the earlier post.

[ajith]

cool - I wasn't sure if 0 counted as an integer on GMAT tests (but - after seeing your reply - I'm guessing it does)

0 is an integer, Period!

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x²+y²=25 eq of the circle

Please let me know as to, how you arrived at the above equation ?

[kstv]

It is a standard eq of a circle with the centre at origin and radius as 5.
but not very sure whether knowledge of this is necessary. Does OG mention any problems involving circles