If m and n are non-zero integers, is mn > nn?Statement 1: |m| = nSt...
Step 1: Decode the Question Stem and Get Clarity
Q1. What kind of an answer will the question fetch?
An "Is" question will fetch an "Yes" or a "No" as an answer.
The data provided in the statements will be considered sufficient if the question is answered with a conclusive Yes or a conclusive No.
Q2. When is the answer an "Yes"?
If mn > nn, the answer to the question is a conclusive Yes.
Q3. When is the answer a "No"?
If mn ≤ nn, the answer to the question is a conclusive No.
Note: When mn = nn, the answer is No.
Q4. What values can m and n take?
From the information available from the question stem, both m and n can take only integer values.
So, we need not worry about values such as 0.5 or 1.2.
However, both m and n can be either positive or negative. Neither can be 0.
Step 2: Evaluate Statement 1 ALONE
Statement 1: |m| = n
We can infer the following information about m and n from the statement.
The modulus of a number is always positive. n = |m|. Hence, n is positive
m can take either positive or negative values.
Example: Let m = -3 and n = 3. |m| = n holds good.
(-3)3 < 33. So, the answer to the question is NO.
Counter Example: Let m = -2 and n = 2. |m| = n still holds good.
(-2)2 = 22. So, the answer to the question is NO.
Notice that we are not able to come up with a counter example. Both examples returned NO as answer.
Not finding a counter example might be our limitation. Let us reason why we seem to be getting NO as answer and will it hold good for all values satisfying statement 1.
When a negative number is raised to an odd power, the result is negative. So, LHS < RHS. Answer is NO.
When a negative number is raised to an even power, the result is positive. So, LHS = RHS. It is still not greater. So, the answer will still be NO.
The values that m and n takes based on statement 1 gives a conclusive answer to the question.
Hence, statement 1 is sufficient.
Eliminate answer options B, C, and E.
Step 3: Evaluate Statement 2 ALONE
Statement 2: m < n
We need to check whether we get a conclusive Yes or No using this statement to determine whether statement 2 alone is sufficient.
Let us look for counter examples
Example: Let m = 2 and n = 3
23 < 33. So, the answer to the question is NO.
Counter Example: Let m = -3 and n = 2
(-3)2 > 22. So, the answer to the question is YES.
The values that m and n takes based on statement 2 do not give a conclusive answer to the question.
Hence, statement 2 is not sufficient.
Eliminate answer option D.
Choice A is the correct answer.