CAMANISHPARMAR wrote:
A person is to be selected at random from the group T of people. What is the probability that the person selected is a member of club E?
1. The probability that a person selected at random from group T is not a member of club D and is not a member of club E is \(\frac{1}{4}\).
2. The probability that a person selected at random from group T is a member of club D and not a member of club E is \(\frac{5}{12}\).
Refer the affixed Venn diagram,
Question stem, probability that the person selected is a member of club E or a+c=?
statement-1:-
Given,he probability that a person selected at random from group T is not a member of club D and is not a member of club E is \(\frac{1}{4}\)
Or,\(n=\frac{1}{4}\)
we have, a+b+c+n=T
Or, (\(a+c)=T-n-b=1-\frac{1}{4}-b=\frac{3}{4}-b\)---------------(1) (T=1 because total probability is always 1)
Since 'b' is not provided, we can't determine a+c.
So, insufficient.
statement-2:-
Given, The probability that a person selected at random from group T is a member of club D and not a member of club E is \(\frac{5}{12}\)
Or, \(b=\frac{5}{12}\)--------------(2)
Since, we don't have info on "n", we can't determine a+c.
So, insufficient.
Now combining, from (1) & (2) we have \(a+c\)=\(\frac{3}{4}\)-\(\frac{5}{12}\)=\(\frac{1}{3}\)
Sufficient.
Ans. (C)
Hope it helps.
Attachments
Probab sum.JPG [ 14.3 KiB | Viewed 1367 times ]
_________________
Regards,
PKN
Rise above the storm, you will find the sunshine