Question

The following are the results of a survey conducted on a small cross-section of students from the Symbiosis Group of institutes, to determine the readership of three magazines: Business India, Outlook and India Today. This survey was conducted in December 2006.

Number of students who read only Business India = 40
Number of students who read only Outlook = 60
Number of students who read only India Today = 110
Number of students who read all three magazines = 30
Number of students who read Business India and India Today, but not Outlook = 20
Number of students who read Business India and Outlook, but not India Today = 50
Number of students who read Outlook and India Today, but not Business India = 40

How many students did not read Business India?

• A. 40
• B. 170
• C. 240
• D. None of these

Hint:

Subtract everyone who touches the Business India circle (only BI, plus both overlaps with BI, plus all three) from the total surveyed.

Answer 1

The Correct Option is D

A quicker route here is to find the total who did read Business India, in any combination, and subtract that from the total surveyed found earlier.

1. Everyone touching the Business India circle: only BI = 40, BI and IT only = 20, BI and OL only = 50, all three = 30. Adding these: 40 + 20 + 50 + 30 = 140 students read Business India in some form.
2. Total surveyed: 350 students, as found in the total surveyed calculation.
3. Students who did not read Business India: subtract the Business India readers from the total: 350 - 140 = 210.

Checking the given options, 40, 170 and 240 are all wrong, and 210 is not listed either.

Let's summarize:

• "Did not read X" equals total surveyed minus everyone who touches the X circle in any way.
• Always add every region that touches Business India before subtracting, not just the "only Business India" figure.

Since 210 does not match any listed number, the correct answer is option (D), None of these.