If n is an integer between 10 and 99, is n < 80?
(1) The sum of the two digits of n is a prime number.
(2) Each of the two digits of n is a prime number.
The OA is the option B.
Why is not sufficient the first statement? Can someone clarify me this?
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If n is an integer between 10 and 99, is n < 80?
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Statement 1:M7MBA wrote:If n is an integer between 10 and 99, is n < 80?
(1) The sum of the two digits of n is a prime number.
(2) Each of the two digits of n is a prime number.
Case 1: n = 11, with the result that the sum of the two digits of n = 1+1 = 2
In this case, n < 80, so the answer to the question stem is YES.
Case 2: n = 83, with the result that the sum of the two digits of n = 8+3 = 11
In this case, n > 80, so the answer to the question stem is NO.
Since the answer is YES in Case 1 but NO in Case 2, INSUFFICIENT.
Statement 2:
Since the tens digit of n must be 2, 3, 5, or 7, n < 80.
Thus, the answer to the question stem is YES.
SUFFICIENT.
The correct answer is B.
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I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
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