Correct Answer: C
Explanation:
From (1) we know the ratio of black socks to white, but that ratio will change when one sock is taken out. To get the new ratio, and hence the probability that the next sock will also be white, we need to know the number of socks of each type. The answer cannot be A or D. Obviously (2) on its own does not get the ratio and so B cannot be correct. But putting the information in both statements together we can solve the problem (24 white socks with a ratio of black to total of 1:3 means that there are 12 black and 24 white socks). The answer is C.