LUANDATO wrote:Is the greatest common factor (GCF) of x and y greater than 1?
(1) x = 40!
(2) y = 40! + 1
The OA is C.
I don't have it clear. Can any expert help me with this DS question please? Thanks.
The correct answer to this question and be either C or E since Statement 1 does not provide any information about y and Statement 2 does not provide any information about x.
(1) and (2) combined:
We have x = 40!, a very large number and y = 40! + 1, another very large number.
Since y - x = 1, x and y are consecutive integers.
Note that two consecutive numbers are co-prime to each other, i.e., no factor other than 1 is common between them. Thus, x and y have only one factor common between them, i.e., 1, which is their GCF = 1. The answer to the question is No. A unique answer. Sufficient.
You may take few examples such as 2 and 3, the GCF = 1; 18 and 19, the GCF = 1; 101 and 102, the GCF = 1, etc.
The correct answer:
C
Hope this helps!
-Jay
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