A bag contains 20 white and some black balls. If the probability of drawing a black ball from the bag is 1.3 times that of drawing a white ball, find the number of black balls in the bag.
When two dice are thrown, what is the probability that sum of the number appeared is 4 or 5?
Two hats are picked at random, what is the probability that all hats are of green colour?
Tom and Jerry throw alternatively a pair of dice. Tom wins if he throws 8 before Jerry throws 7 and Jerry wins if he throws 7 before Tom throws 8. Find...
In a box there are 6 red, 12 blue, and 18 yellow cards. One card is picked up randomly. What is the probability that it is neither red nor yellow?
A box of bulbs is inspected by examining three randomly selected bulbs drawn without replacement. If all the three bulbs are non-defected, the box is ap...
From a bag containing 12 white and 15 yellow ribbons, find the probability of picking 2 ribbons of each type at random.
A bag contains 19 white and some black balls. If the probability of drawing a black ball from the bag is twice that of drawing a white ball, find the nu...
Two cards are drawn at random from a pack of 52 cards. What is the probability that either both are black or both are queens?
In a box there are 12 orange, 5 white, and 7 blue balls. One ball is picked up randomly. What is the probability that it is neither white nor blue?
...Given that E and F are events such that P(E) = 0.7, P(F) = 0.4 and P(E ∩ F) = 0.3, find P(E|F) and P(F|E)