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How many students in a room are currently taking either geography or 01 Dec 2021, 08:00
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C
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81% (00:59) correct 19% (01:25) wrong based on 107 sessions

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How many students in a room are currently taking either geography or history, but not both?

(1) The number of students in the room who are taking at least one of the subjects history and geography is 127.
(2) The number of students in the room who are taking both geography and history is 46.
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C
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How many students in a room are currently taking either geography or 02 Dec 2021, 06:22
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Total students = students taking only history + students taking only geography + students taking both.

Combining (1) and (2):

127 = students taking only history + students taking only geography + 46

So, students taking only history + students taking only geography = 127 - 46 = 81

Sufficient. So, C.
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How many students in a room are currently taking either geography or 04 Dec 2021, 23:01
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We don't know the number of students taking neither of the 2 subjects . Why is it not E ?
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How many students in a room are currently taking either geography or 05 Dec 2021, 11:00
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Bunuel
How many students in a room are currently taking either geography or history, but not both?

(1) The number of students in the room who are taking at least one of the subjects history and geography is 127.
(2) The number of students in the room who are taking both geography and history is 46.
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Wouldn't the Answer be E. since we don't know the number of students who aren't taking any of the 2 subjects. How do we assume that all students must take one of the two or both the subjects ?
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How many students in a room are currently taking either geography or 02 Jan 2022, 19:41
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I got the answer as E. Why is it C? Bunuel, chetan2u, GMATBusters KarishmaB could you please help us with the official answer/ explanation? Thanks!
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How many students in a room are currently taking either geography or 02 Jan 2022, 20:32
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How many students in a room are currently taking either geography or history, but not both?

Let the number of students taking only geography be g, only history be h and both history and geography be B.
So we are looking for g+h.

(1) The number of students in the room who are taking at least one of the subjects history and geography is 127.
This means these 127 students are part of g or h or B.
But g+h+B=127
Insufficient

(2) The number of students in the room who are taking both geography and history is 46.
Here, we are given B=46.
Nothing about g and h.
Insufficient


Combined
Statement I - statement II = (g+h+B)-B=127-46
g+h=81
Sufficient
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How many students in a room are currently taking either geography or 03 Jan 2022, 02:09
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ritzu
I got the answer as E. Why is it C? Bunuel, chetan2u, GMATBusters KarishmaB could you please help us with the official answer/ explanation? Thanks!
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Check this video first: https://youtu.be/HRnuURqGhmg

Now consider : In this question we are looking at only the blue, green and yellow regions. Anything outside that is neither asked nor given so we should ignore it.

No of students taking only one subject but not both = Blue + Yellow
No of students taking at least one subject = Blue + Green + Yellow
No of students taking both subjects = Green
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