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If n is an integer and 3n/7 is a perfect square
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27 Aug 2018, 09:47
27 Aug 2018, 09:47
Expert Reply
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Question Stats:
80% (00:29) correct
20% (00:16) wrong based on 35 sessions
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If n is an integer and \(\frac{3n}{7}\) is a perfect square, the smallest possible value of n is
A. 3
B. 7
C. 21
D. 42
E. 147
A. 3
B. 7
C. 21
D. 42
E. 147
Re: If n is an integer and 3n/7 is a perfect square
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28 Aug 2018, 06:51
28 Aug 2018, 06:51
1
Just plug the value and see the smallest value which will give a square. 21 is the answer which gives 9 (a square of 3)
Re: If n is an integer and 3n/7 is a perfect square
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07 Sep 2018, 19:26
07 Sep 2018, 19:26
Carcass wrote:
If n is an integer and \(\frac{3n}{7}\) is a perfect square, the smallest possible value of n is
A. 3
B. 7
C. 21
D. 42
E. 147
A. 3
B. 7
C. 21
D. 42
E. 147
\(\frac{3n}{7}\) = perfect square.
Note: As 3 is not divisible by 7 , n must be a multiple of 7.
So, we must pick up a number in such a manner thus after division still we can form a perfect square.
27 = 7*3
So,
\(\frac{3*21}{7}\) = \(3^2\)
Thus the best answer is C.
