ankitnoida2018 wrote:
A drawer contains 36 socks, and 2 socks are selected at random without replacement. What is the probability that both socks are black?
(1) The probability is 4/9 that the first sock is black.
(2) The number of white socks in the drawer is 4 more than the number of black socks.
From either statement, one can conclude that there are 16 black and 20 white socks. So the desired probability is 16/36 x 15/35
D.
Hi,
While evaluating both options you have assumed there are only white and black socks. Which is incorrect.
While in 1 we know the exact number of black socks and total number of socks. So we can conclude it is sufficient condition.
In option 2 we are given relative number of white socks as compared to black. But it is nowhere state black + white = total number of socks.
Hence it is insufficient.
Please give kudos if you like the explanation.