Set Theory - Quant/Math - CAT 2009
Question 4 the day:
May 7, 2003
The question for the day is from the topic of Set Theory.
- In a survey on the popularity of joggery, aerobics and swimming, it was found that 22 swam, 13 jogged and did aerobics, 10 jogged and swam, 4 jogged, did aerobics and swam, 9 did aerobics and swam, 32 jogged and 29 did aerobics. Find the number of people surveyed?
| (1) |
35 |
| |
(2) |
55 |
| (3) |
45 |
| |
(4) |
Cannot be determined |
Correct Answer - (2)
Solution:
n(J) = 32, n(A) = 29, n(S) = 22
n(J A) = 13, n(JS) = 10, n(AS) = 9, n(JAS) = 4
Now, n(J AS) = n(J) + n(A) + n(S) - n(JA) - n(JS) - n(AS) + n(JAS) = 32 + 29 + 22 - 13 - 10 - 9 + 4 = 55
Therefore, the number of people surveyed = 55
|
