If j and k are integers and jk = 12, what is the value of k ?

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jk = 12 and j,k are integers.

From Statement 1,
j/6 = integer. This implies j can be -6, -12, 6, 12
This gives us multiple values of k. NOT SUFFICIENT

From Statement 2,
k/12 = integer. This implies k = -2, -4, -6, -12, 2, 4, 6, 12
Mutiple values of k, NOT SUFFICIENT

Combining both the statement,
We can have two pairs of values for j,k: (6, 2) and (-6, -2)
We still do not have a unique answer. NOT SUFFICIENT

Correct Option E

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 equations ensures a solution.

If j and k are integers and jk = 12, what is the value of k ?

(1) j/6 is an integer

(2) k/2 is an integer.

In the original condition we have 2 variables (j,k) and 1 equation (jk=12) thus we need 1 more equation to match the number of variables and equations. Since there is 1 each in 1) and 2), D is likely the answer.
In case of 1), the multiple of j=6 -> 6,-6 --> k=2,-2 therefore the answer is not unique, and the condition is not sufficient
In case of 2), the multiple of k=2 -> 2,-2, therefore the answer is not unique, and the condition is not not sufficient
Using both 1) & 2) k=2,-2 therefore it is not unique and thus the conditions are not not sufficient. therefore the answer is E

=> j and k are integers
=> jk = 12
Find k ?

jk =12 = 1*12 = 2*6 =3*4 = -1 *-12 = -2* -6 = -3 * -4


(1) j/6 is an integer
By looking at above and j/6= integer => j = {12,6, -6, -12} => k = {1,2, -1, -2}
Insufficient

(2) k/2 is an integer.
By looking at above and k/2= integer => k = {2,4,6,12, -2, -4, -6, -12)
Insufficient

1+2
=> k = -2 or 2
Insufficient

Answer: E

Hello everyone,

Where are the answers (A,B,C...) of the posted DS questions? I just see the CORRECT one!

Regards,
Sep.

This is a data sufficiency question. Options for DS questions are always the same.

The data sufficiency problem consists of a question and two statements, labeled (1) and (2), in which certain data are given. You have to decide whether the data given in the statements are sufficient for answering the question. Using the data given in the statements, plus your knowledge of mathematics and everyday facts (such as the number of days in July or the meaning of the word counterclockwise), you must indicate whether—

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient to answer the question asked.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient to answer the question asked.
C. BOTH statements (1) and (2) TOGETHER are sufficient to answer the question asked, but NEITHER statement ALONE is sufficient to answer the question asked.
D. EACH statement ALONE is sufficient to answer the question asked.
E. Statements (1) and (2) TOGETHER are NOT sufficient to answer the question asked, and additional data specific to the problem are needed.

I suggest you to go through the following posts:
ALL YOU NEED FOR QUANT.
Ultimate GMAT Quantitative Megathread

Hope this helps.

The answer is E
From First statement we have
Two values of j i.e 12 and 6
From second statement we have 4 values of k
2,4,6,12
Taken together we still can not find the value of k
Hence E

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Dear Bunuel,

It helped ! Thank you for the post.
Sep.

jk = 12 =1*12 or, =2*6 or, =3*4
1) j/6 is an integer. j can be either 12 or 6. not sufficient
2) k can be 12, 6, 4 or 2. not sufficient
Together, when j is 12, k is 1, which will negate the second statement. so only option j =6 and k =2.
C is the answer

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