A jar contains 54 marbles each of which is in one of the colours blue, green and white. The probability of drawing a blue marble is and the probability of drawing a green marble is . How many white marbles does the jar contain?

Three dice are thrown simultaneously. Find the probability of getting the same number on all the three dice.

Two dice are rolled and the product of the outcomes (numbers) are found. What is the probability that the product so found is a prime number?

A bag consists of 100 shirts of which 88 are good, 8 have minor defects and 4 have major defects. A trader A will accept only the shirt which are good, but the trader B will not accept the shirts which have major defects. One shirt is drawn at random. What is the probability that it is acceptable by (i) A (ii) B?

A bag contains 12 balls out of which x balls are white. (i) If one ball is drawn at random, what is the probability that it will be a white ball. (ii) If 6 more white balls are put in the bag and if the probability of drawing a white ball will be twice that of in (i), then find x.