Interesting DS Question

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Interesting DS Question

by dhanda.arun » Sat Sep 27, 2008 2:21 pm
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Hi,
The OA is E.
Kindly Help

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by Morgoth » Sat Sep 27, 2008 5:21 pm
Question stem : is k square of an integer?

Statement (1)
k is divisible by 4

if k=4, k = 2^2, yes
if k=8, then k is not a square of an integer. Insufficient.

Statement (2)
k is divisible by 4 prime numbers

if k = 2^2 * 3^2 * 5^2 * 7^2 = yes k is square of an integer.
if k = 2*3*5*7 = no k is not a square of an integer. Insufficient.

Combining (1) & (2)

divisible by 4, exactly 4 different prime numbers

if k = 2^2 * 3^2 * 5^2 * 7^2- satisfies both the conditions and yes k is square of an integer.

if k = 2^2 * 3* 5 * 7 satisfies both the conditions and no k is not a square of an integer. Insufficient.

Thus, E is the answer.