 Welcome to the session I am the picker here. Let's discuss a question which says if box contains five red balls and some blue balls if the probability of drawing a blue ball is double that of a red ball determine the number of blue balls in the pack. Now we know that the probability of an event E is equal to number of outcomes favorable or possible terms of the experiment. So this is a key idea behind our question. We will take the help of this key idea to solve the above question. So let's start the solution. Now according to the question a bag contains five red balls and some blue balls. Let the number of in the bag is equal to x the total number of balls in the bag is equal to 5 plus x because there are five red balls in the bag that is the number of x is equal to 5 the ball is the event the ball is red the probability of the event B is equal which is x is equal to that is the probability of the red ball is equal to 5 the probability of a blue ball is double that of a red ball. So this implies now probability of blue ball is and this is equal to the probability of red ball is 5 this implies is equal to 0 5 plus this implies is equal to 2 into 5 which is equal to 10 2 blue balls in the bag. His answer for the above question is 10. I hope the solution is clear to you. Bye. Take care.