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If b is an integer greater than 1, ab=?
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19 Jul 2016, 01:45

tinalongmao wrote:

As for statement 1: if b^a=1, we can have log(b)1=a therefore, a=0 => ab=0

Could I get the conclusion as above? ( using the function of log)

Yes, using log could be another way to solve this question.

And for statement 2, you can say that since the value of 'a' is unknown, you cannot find 'ab'. Thus, B would be insufficient in that case.
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Re: If b is an integer greater than 1, ab=?
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20 Jul 2016, 07:17

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Top Contributor

MathRevolution wrote:

If b is an integer greater than 1, then ab=?

1) b^a = 1 2) b = 2

Target question:What is the value of ab?

Given: b is an integer greater than 1

Statement 1: b^a = 1 There are 3 possible cases to consider: case a: b = 1 and a is any number case b: b = -1 and a is an even integer case c: b = any number and a = 0

Since we're told that b is an integer greater than 1, we can rule out cases a and b, which means it MUST be the case that a = 0, in which case ab = 0 Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: b = 2 Since we have no information about the value of a, we cannot determine the value of ab Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

Re: If b is an integer greater than 1, ab=?
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25 Jul 2016, 05:44

Since there are 2 variables in the original condition, there is a high chance that C is the correct answer. However, we have to apply the common mistake type 4(A) since it is an integer question, one of key questions. In case of con 1), since we have a=0, we get ab=0. The answer is unique and the condition is sufficient. Hence, the correct answer is A.

- Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.
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Re: If b is an integer greater than 1, ab=?
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11 Apr 2018, 10:23

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