A bag has 100 balls out of which there is one green ball. 50 balls are randomly selected. What is probability that the green ball is selected.
P = 99c49/100C50 = 1/2
Explanation P = success cases/all cases All cases = 100C50 Success cases = 1 green ball and any remaining any 49 ball i.e. 99C49
So P=99c49/100C50 = (99!/(49!*50!))/(100!/(50!*50!)) = 1/49!/100/50! = 50/100 = 1/2
A bag contains 5 white, 4 red and 3 black balls. A ball is drawn at random from the bag, what is the probability that it is not black?
A bag contain 5 red balls and some blue balls. If the probability of drawing a blue ball from the bag is four time that of a red ball, then find the number of blue balls in the bag.
There are 8 boys and 5 girls in a class. If four students are selected at random, what is the probability that 2 girls and 2 boy are selected?
There are 12 boys and 9 girls in a class. If three students are selected at random, what is the probability that 1 girl and 2 boys are selected?
