If C and D are unique integers, does C = 0?

Question

(1) CD = C^2
(2) D = 4

GMATinsight · Answer

Question : Is C=0 ?

Statement 1: CD = C^2 
Since C and D are Integers therefore the above equation can be re-written as

C (C-D) =0
i.e. either C=0 or C=D
but Since C and D are distinct therefore C can't be equal to D
therefore , C= 0
SUFFICIENT

Statement 2: D = 4 
i.e. C can be any Integer value other than 4, But this doesn't provide us any unique value therefore
NOT SUFFICIENT

Answer: Option  A

mridupawandas · Answer

IS C=0? A=> c^2-CD=0 and C not equal to D that implies Cmust be 0 Hence sufficient .. Statement2 tells D=4 not sufficient Hence A.

Bunuel · Answer

VERITAS PREP OFFICIAL SOLUTION

Correct Answer: A

From statement 1, we know that, if C was NOT 0, the equation could be manipulated to tell us that D = C. Since the question says that is not possible, we know that C must be 0, so statement 1 is sufficient. Statement 2 only tells us that C is not 4. C could be 0, but it could also be anything else with the exception of 4. A is the correct answer.

dharam831 · Answer

If C and D are unique integers, does C = 0?

(1) CD = C^2
(2) D = 4

State (1) C*D = C*C
C is not equal to D So, C=0
Sufficient

State(2) Not sufficient

Answer - A

iikarthik · Answer

C and D are unique .so C is not equal to D

option1: CxD=C^2 to achive this only possibilty is D=-C.here both are unique and their product gives C^2
Here C cant be zero as if c=0,the CD= C^2=0

Option2: D=4..Not sufficient

Hence answer is 'A'

palaknayyar · Answer

From statement 1: Clearly, C cannot be anything other than zero. I tried a number of iterations with whole numbers, decimals, but C can only be 0 as no other number when multiplied with D will equal C^2. Therefore, strike off BCE.

Statement 2: very clearly not enough to answer the question.

Final answer: A

Statement 2: very clearly not enough to answer the question.

Final answer: A

rapidash · Answer

What if D= -C . can we still say that statement 1 is sufficient?

Bunuel · Answer

The question asks whether C = 0 and (1) says that CD = C^2:

CD = C^2;
CD - C^2 = 0;
C(D - C) = 0;
C = 0 or D = C. But since we are told that D ≠ C ( C and D are unique integers ), then we are only left with C = 0.

Now, D = -C, would mean that D = -C = -0 = 0 (D = C = 0), which is not possible since we are given that D ≠ C.

bumpbot · Answer

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If C and D are unique integers, does C = 0?

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GMAT Data Sufficiency (DS) Questions

If C and D are unique integers, does C = 0?

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