Og 11 #146

[apoorva.srivastva]

Is n an integer?

1.) n² is an integer
2.) sqaure root of n is an integer

Please help ... confused abt St 1

[genius_in_the_gene]

1) n^2 is an int.
so n^2 can be any int 2,3,4,5,6 and not necessarily a perfect square.
if n^2=5, then n is not an int
if n^2=4, then n is an int.

2) sqrt n = an int
so n would be an int.
IMO B

[lazyjava]

Agreed
1) Is insufficient by plugging in numbers:
if n^2 = 4 -> n = 2
but n^2 = 3 -> n = fractional
INSUFFICIENT

2) if sqrt n = integer, squaring the sqrt n will yield an integer
SUFFICIENT

hence B

[Lock]

Agree with Genius.
The same line of reasoning.

[apoorva.srivastva]

[quote=genius_in_the_gene;761360]1) n^2 is an int.
so n^2 can be any int 2,3,4,5,6 and not necessarily a perfect square.
if n^2=5, then n is not an int
if n^2=4, then n is an int.


Thanks all.. it was silly miss from my side...!!!

[finsisher]

easy one its B