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Bunuel
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For the system of equations given, what is the value of c? 22 Aug 2019, 22:40
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D
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Difficulty:

15% (low)

Question Stats:

85% (00:48) correct 15% (01:15) wrong based on 91 sessions

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6a - 5 = c
7b - a = 9
8 - c = d

For the system of equations given, what is the value of c?

(1) a = 8

(2) d = 6



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D
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For the system of equations given, what is the value of c? 23 Aug 2019, 04:26
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Looking at the equations given in the question, there are two equations where the variable c is defined in terms of another variable. They are:

6a – 5 = c and

8 – c = d which can be simplified to c = 8 – d.

Therefore, any statement that tells us anything about a or d is giving us sufficient data.

Statement I gives us data about a, from which we can find out the value of c to be 43. Statement I alone is sufficient.
Possible answer options are A or D. Answer options B, C and E can be eliminated.

Statement II gives us data about d from which we can find out the value of c to be 2. Statement II alone is sufficient. Answer option A can be eliminated.

The correct answer option is D, IMO.

Hope this helps!
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For the system of equations given, what is the value of c? 23 Aug 2019, 04:33
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ArvindCrackVerbal
Looking at the equations given in the question, there are two equations where the variable c is defined in terms of another variable. They are:

6a – 5 = c and

8 – c = d which can be simplified to c = 8 – d.

Therefore, any statement that tells us anything about a or d is giving us sufficient data.

Statement I gives us data about a, from which we can find out the value of c to be 43. Statement I alone is sufficient.
Possible answer options are A or D. Answer options B, C and E can be eliminated.

Statement II gives us data about d from which we can find out the value of c to be 2. Statement II alone is sufficient. Answer option A can be eliminated.

The correct answer option is D, IMO.

Hope this helps!
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but both statements lead to different values of C....nothing fishy in that???
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For the system of equations given, what is the value of c? 23 Aug 2019, 04:39
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thyagi
ArvindCrackVerbal
Looking at the equations given in the question, there are two equations where the variable c is defined in terms of another variable. They are:

6a – 5 = c and

8 – c = d which can be simplified to c = 8 – d.

Therefore, any statement that tells us anything about a or d is giving us sufficient data.

Statement I gives us data about a, from which we can find out the value of c to be 43. Statement I alone is sufficient.
Possible answer options are A or D. Answer options B, C and E can be eliminated.

Statement II gives us data about d from which we can find out the value of c to be 2. Statement II alone is sufficient. Answer option A can be eliminated.

The correct answer option is D, IMO.

Hope this helps!

but both statements lead to different values of C....nothing fishy in that???
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As long as you are getting a unique value when using a statement independently, that statement is sufficient. Data sufficiency is not about getting the same answer using the individual statements.

Yes, it is true that, on the GMAT, 99% of the times, when the answer is D, the answers that you get from the individual statements will match.
Hope that helps!
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For the system of equations given, what is the value of c? 16 Oct 2019, 04:51
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Bunuel
6a - 5 = c
7b - a = 9
8 - c = d

For the system of equations given, what is the value of c?

(1) a = 8
(2) d = 6
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6a-5=c; 8-c=d; 6a-5=8-d

(1) a = 8: 6a-5=8-d…6(8)-5=8-d…d=-35…d=8-c…c=8-(-35)=43 sufic.

(2) d = 6: 8-c=d…c=8-d…c=8-6=2; sufic.

Answer (D)

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