Question

A box 'A' contains 2 white and 4 black balls. Another box 'B' contains 5
white and 7 black balls. A ball is transferred from box 'A' to box 'B' and
a ball is drawn at random from box 'B'. What is the probability that it
will be black?

Answer 1

because there are a large number of black balls in the box(around 8 balls)

Answer 2

As in box B all are black balls. If we transfer one from box B then the remaining balls are 6 and all are black.

Therefore, probability of getting black ball in box B= 6/6

=1. Ans

Hope it is right.