A box contains 90 discs which are numbered from 1 to 90. If one disc is drawn at random from the box, find the probability that it bears a two-digit number.

A box contains 90 discs which are numbered from 1 to 90. If one disc is drawn at random from the box, find the probability that it bears : a number divisible by 5.

A box contains 90 discs which are numbered from 1 to 90. If one disc is drawn at random from the box, find the probability that it bears : a perfect sequare number

A box contains 90 discs which are numbered from 1 to 90. If one disc is drawn at random from the box, find the probability that it bears a perfect square number.

A box contains 12 balls out of which x are black. If one ball is drawn at random from the box, what is the probability that it will be a black ball ?

A box contains 3 blue, 2 white and 4 red Marbles. If a marble is drawn at random from the box then what is the probability that it will be : white

A box contains 3 blue, 2 white, and 6 red marbles. If a marble is drawn at random from the box, what is die probability that it will be red?

A box contains 12 balls out of which x are black. If one ball is drawn at random from the box, what is the probability that it will be a black ball ? If 6 more balls are put in the box, the probability of drawing a black ball is now double of what it was before. Find x .

20 cards are numbered from 1 to 20. One card is then drawn at random. What is the probability that the number on the card will be : odd?

12 tickets are numbered from 1 to 12 one ticket is drawn at random, then the probability of the number to be divisible by 2 or 3 is:

A bag contains 20 cards numbering from 1, 2, 3......20. One card is drawn from the bag. Find the probability that it has a prime number on it.