shekharvineet wrote:
Need help on this question which is explained in the Number Properties book by Manhattan. According to Manhattan, the OA is C, but to me, the OA should be A.
If n is an integer and n^3 is between 1 and 100, inclusive, what is the value of n?
(1). n = 2k+1, where k is an integer.
(2). n is a prime number.
We know that n>0 because n^3 is between 1 and 100, so n is a positive integer. The value of n could be 1, 2, 3, and 4.
Statement 1: n = 2k+1. So n is an odd number. So n is either 1 or 3. According to
MGMAT, statement 1 is not sufficient to answer the question because n could be either 1 or 3 and so there is not a unique value of n as it yields two possible values. But this is where I beg to differ. According to me, the value of n could be only 3 (n = 2*1+1).
Tell me where I am wrong.
If n is an integer and n^3 is between 1 and 100, inclusive, what is the value of n?n is an integer and \(n^3\) is between 1 and 100, inclusive, means that n could be 1, 2, 3 or 4 (but not 5 or more since 5^3 = 125 > 100).
(1) n = 2k+1, where k is an integer --> n is an odd number --> n could be 1 or 3. Not sufficient.
(2) n is a prime number --> n could be 2 or 3. Not sufficient.
(1)+(2) n could be only 3. Sufficient.
Answer: C.
shekharvineet wrote:
Need help on this question which is explained in the Number Properties book by Manhattan. According to Manhattan, the OA is C, but to me, the OA should be A.
If n is an integer and n^3 is between 1 and 100, inclusive, what is the value of n?
(1). n = 2k+1, where k is an integer.
(2). n is a prime number.
We know that n>0 because n^3 is between 1 and 100, so n is a positive integer. The value of n could be 1, 2, 3, and 4.
Statement 1: n = 2k+1. So n is an odd number. So n is either 1 or 3. According to
MGMAT, statement 1 is not sufficient to answer the question because n could be either 1 or 3 and so there is not a unique value of n as it yields two possible values. But this is where I beg to differ. According to me, the value of n could be only 3 (n = 2*1+1).
Tell me where I am wrong.
As for your doubt: \(n=2k+1\), where k is an integer is a formula of an odd number so you can get ANY odd number with it, including 1: if k = 0 then \(n=2k+1=1\).
Hope it helps.
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