The number 14x52y is divisible by 11.

Question

The number 14x52y is divisible by 11. What is the value of x, if x and y are whole numbers.

I. y = 1
II. y = 5

Source - Indian MBA college entrance test

ProfChaos · Answer

From St1:
y=1, thus x can be 7 and the number 147521 is divisible by 11

From St2:
y=5, thus x can be 0 (x cannot be 11) and the number 140525 is divisible by 11

Now we are getting different values of x from different statements

Hence, I think answer choice E is the correct one here and not D

Someone please explain if I am wrong

historyfan10 · Answer

Hello,

I think this question is biased. Usually, GMAT DC questions should be consistent in the statements. This means they should not lead to two different solutions as it is the case here with the two different possibilities for x.

ProfChaos · Answer

There are GMAT DC questions in which St1. leads to two values of the variable and St.2 leads to two values and even when both the statements are combined, there is no common case, in those cases, choice E is the correct choice and there are questions where a combination of statements has narrowed the value down to the common case, in those cases, answer choice C is the correct choice

I hope you have come across both the above type of scenarios.

Bunuel · Answer

That's not correct.

On the GMAT, two data sufficiency statements always provide TRUE information and these statements never contradict each other.

So, for example, we cannot have y = 1 from statement (1) and y = 5 from statement (2), as in this case statements would contradict each other.

Or for example in YES/NO DS questions we cannot have answer YES from statement (1) and answer NO from statement (2), as in this case statements also would contradict each other.

So, the above question is flawed.

ProfChaos · Answer

I agree with what Bunuel said.
On solving St1 and St2, values shouldnt contradict each other.

But  Bunuel , help me with the below example,

Question: Find value of x
St.1: Quadratic eqn of x of degree 2 --> on solving we get two values of x (let x=3/-2) --> insufficient
St.2: Quadratic eqn of x of degree 2 --> on solving we get two values of x (let x=5/3) --> insufficient

Now A/B/D are not our answer choices
So, we combine both statements and check if C is correct, else E would be the answer.
On combining both statements, we get a value for x. i.e x=3
Hence correct answer choice is C

Bunuel · Answer

CASE 1: 
From (1) x = 3 or x = -2
From (2) x = 3 or x = 5

When considering together x = 3. Sufficient.

Answer: C.

CASE 2: 
From (1) x = 3 or x = -2
From (2) x = 1 or x = 5

The question is flawed. The statements contradict each other.

CASE 3: 
From (1) x = 3 or x = -2 or x= 7
From (2) x = 3 or x = 5 or x= 7

When considering together x = 3 or x = 7. Not sufficient.

Answer: E.

The number 14x52y is divisible by 11.

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GMAT Data Sufficiency (DS) Questions

The number 14x52y is divisible by 11.

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

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My Rewards