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If 53 students are enrolled in both the CS103 (Algorithms and Data Str

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Manager
Joined: 27 Jul 2014
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If 53 students are enrolled in both the CS103 (Algorithms and Data Str  [#permalink]

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02 Feb 2016, 16:21
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Question Stats:

76% (01:19) correct 24% (01:09) wrong based on 73 sessions

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If 53 students are enrolled in both the CS103 (Algorithms and Data Structures) and the M101 (Mathematics for Computer Science) classes, how many of the CS103 students are not enrolled in M101?

(1) 72 students are taking M101.
(2) 59 students are taking CS103
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Re: If 53 students are enrolled in both the CS103 (Algorithms and Data Str  [#permalink]

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02 Feb 2016, 16:22
HI Experts
PLZ explain logic behind OA

I don't agree with OA
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Re: If 53 students are enrolled in both the CS103 (Algorithms and Data Str  [#permalink]

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02 Feb 2016, 17:23
kanigmat011 wrote:
If 53 students are enrolled in both the CS103 (Algorithms and Data Structures) and the M101 (Mathematics for Computer Science) classes, how many of the CS103 students are not enrolled in M101?

(1) 72 students are taking M101.
(2) 59 students are taking CS103

I believe you are getting confused with the extra bit of information regarding CS103 and M101. Refer to the attached 2X2 Matrix for this question.

You are given that CS103 students not taking M101 = 53

Attachment:

QUESTION.jpg [ 12.05 KiB | Viewed 1297 times ]

Per statement 1, total number of students taking M101 = 72. You can not calculate 'x'. Not sufficient.

Attachment:

S1.jpg [ 12.36 KiB | Viewed 1297 times ]

Per statement 2, total number of students taking CS103=59 and out of these, 53 take both the courses. Thus the ones taking CS103 only = 59-53 = 6. Hence sufficient.

B is thus the correct answer.

Hope this helps.

Attachment:

S2.jpg [ 13.92 KiB | Viewed 1295 times ]
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Joined: 27 Jul 2014
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Re: If 53 students are enrolled in both the CS103 (Algorithms and Data Str  [#permalink]

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02 Feb 2016, 18:53
1
Engr2012 wrote:
kanigmat011 wrote:
If 53 students are enrolled in both the CS103 (Algorithms and Data Structures) and the M101 (Mathematics for Computer Science) classes, how many of the CS103 students are not enrolled in M101?

(1) 72 students are taking M101.
(2) 59 students are taking CS103

I believe you are getting confused with the extra bit of information regarding CS103 and M101. Refer to the attached 2X2 Matrix for this question.

You are given that CS103 students not taking M101 = 53

Attachment:
QUESTION.jpg

Per statement 1, total number of students taking M101 = 72. You can not calculate 'x'. Not sufficient.

Attachment:
S1.jpg

Per statement 2, total number of students taking CS103=59 and out of these, 53 take both the courses. Thus the ones taking CS103 only = 59-53 = 6. Hence sufficient.

B is thus the correct answer.

Hope this helps.

Attachment:
S2.jpg

Hi Engr2012,

Thanks for explaining this,

But no where its mentioned that its just two classes and what if there are more than 2 classes.

Aren't we missing the case of none of the two

Apart from 6 there can be few students who have not opted for either of the calls so they should also be part of answer.

Is there something I am missing?
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If 53 students are enrolled in both the CS103 (Algorithms and Data Str  [#permalink]

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02 Feb 2016, 18:59
kanigmat011 wrote:

Hi Engr2012,

Thanks for explaining this,

But no where its mentioned that its just two classes and what if there are more than 2 classes.

Aren't we missing the case of none of the two

Apart from 6 there can be few students who have not opted for either of the calls so they should also be part of answer.

Is there something I am missing?

You can not assume that there are more courses if you are not provided any sort of a hint to think that. If what you are saying is indeed true, then most of the DS overlapping set questions will have an answer E.

For your 2nd question, you can clearly see that the value of 'x' is NOT dependent on the number of students not taking either as shown in the picture accompanying statement 2. You are given total number of students taking CS course while also told that students taking both courses =53. The question asks you about the students who have taken the CS course and NOT MS course and this clearly is = total students taking CS course - total students taking both the courses as shown in the picture.

Nowhere am I using the information of the number of students opting for none of the 2 courses. Information for students taking none would have been useful for lets say with the given information, the question would have asked about the total number of students not opting M101 course or total number of students not opting CS101 course.

Hope this helps.
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Re: If 53 students are enrolled in both the CS103 (Algorithms and Data Str  [#permalink]

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13 Jul 2017, 14:44
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Re: If 53 students are enrolled in both the CS103 (Algorithms and Data Str   [#permalink] 13 Jul 2017, 14:44
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