There are two possibilities, the missing card is a club card or the missing card is not a club card. The probability that the missing card is a club card is ¼, and the probability that it is not a club card is ¾.
Case I: When the missing card is a club card:
The probability that the two cards drawn are club cards = \(\frac{12C_2}{51C_2} = \frac{12\times11}{51\times50}\)
Case II: When the missing card is not a club card:
The probability that the two cards drawn are club cards = \(\frac{13C_2}{51C_2} = \frac{13\times12}{51\times50}\)
By Baye’s Rule,
The required probability = \(\frac{\frac{1}{4}\times\frac{12\times11}{51\times50} }{ \frac{1}{4}\times\frac{12\times11}{51\times50}+\frac{3}{4}\times\frac{13\times12}{51\times50 }}= \frac{11}{50}\)
Hence, option C is the correct option.
Direction: A few statements have been given in each of the following questions. Analyse the given statements and answer whether the data given in the statements is sufficient to answer the question or not.
A box contains 20 tops of the same size and pattern. Each top is either white, black, or grey in colour. Find the number of black tops in the box.
Statement I: The probability of picking a black top is the same as the probability of picking a grey top.
Statement II: The number of grey tops is more than that of white tops.
Statement III: The probability of picking a white top is 20%.