A bag contains 12 balls out of which some are white and the others are red. If the probability of drawing a white ball at random from the bag is `2/3`, then find how many red balls of there in the bag.

A bag contains 4 white balls and some red balls.If the probability of drawing a white ball from the bag is (2)/(5), find the number of red balls in the bag.

A bag contains 5 red balls and some blue balls. If the probability of drawing a blue ball from the bag is thrice that of a red ball, find the number of blue balls in the bag.

A bag contains 20 balls out of which x balls are white.If one ball is drawn at random,the probability drawing a white ball is y.Now place this ball and 10 more white balls in the bag.Now if a ball is drawn from the bag,the probability of drawing the white ball is 2y. Find x.

A bag contains 6 red balls and some blue balls. If the probability of drawing a blue ball from the bag is twice that of a red ball,find the number of blue balls in the bag.

A bag contains 15 white and some black balls. If the probability of drawing a black ball from the bag is thrice that of drawing a white ball find the number of black balls in the bag.

A bag contains 15 white and some black balls. If the probability of drawing a black ball from the bag is thrice that of drawing a white ball, find the number of black balls in the bag.

A bag contains 5 red balls and some blue balls. If the probability of drawing a blue ball is double that of a red ball, find the number of blue balls in the bag.