A box has

blue and

red balls. One ball is drawn at random and not replaced. Its colour is also not noted. Then another ball is drawn at random. What is the probability of second ball being blue?

contexto.140

3 years ago

Given that the box has

blue and

red balls.

Let us consider

be the event that first ball drawn is blue and

be the event that first ball drawn is red.

And, E is the event that second ball drawn is blue.

Now, the probability of E is:

Therefore, the required probability is