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data sufficency square root

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data sufficency square root

by budetta4 » Mon Feb 01, 2010 3:51 am
I s the square root of teh integer X an integer?
(1) the units digit of x is 2
(2) x is divible by 3

(1) alone is sufficent
I found this question on 800 score but I didn't understand the explanation
thanks in advance
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by thephoenix » Mon Feb 01, 2010 3:58 am
all the perfact square no. which is an int in number system can have any of the 0,1,4,9,6,5 at its unit place


rest all no's after taking ruts will result in non int no...
with 2 at unit place its square root will be a non int value

hence suff

s2)
6 div by 3 but its root is non int
where as 36 div by 3 its root is int
hence insuff
hence A
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by sars72 » Mon Feb 01, 2010 5:35 am
thephoenix wrote:all the perfact square no. which is an int in number system can have any of the 0,1,4,9,6,5 at its unit place


rest all no's after taking ruts will result in non int no...
with 2 at unit place its square root will be a non int value

hence suff

s2)
6 div by 3 but its root is non int
where as 36 div by 3 its root is int
hence insuff
hence A
omg! can't believe I was so naive. Despite having attempted so many problems to date, I ended up marking statement 1 as insufficient because the answer I got NO, it cannot be square root. I confused this NO with not sufficient and ended up corssing off choices A and D. Thank god I've realized my folly before it was too late.
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