question_answer

A box contains 40 marbles of red and blue colour. If a marble is picked at random, the probability of picking a blue marble is\[\frac{3}{8}\]. Rana takes out one red marble and nine blue marbles and then picks a marble at random. Find the probability that it is a blue marble.

A)  \[\frac{4}{5}\]                                  

B)  \[\frac{2}{5}\]

C)  \[\frac{7}{40}\]                               

D)  \[\frac{1}{3}\]