A box contains 90 discs which are numbered from 1 to 90. If one disc is selected at random from the box, find the probability that it bears (1) a two-digit number (ii) a perfect square number (iii) a number divisible by 5.

The integer is selected at random from 1 to 25. The probability that it is a prime number is

A box contains 3 blue, 2 white, and 4 red marbles. If a marble is selected at random from the box, what is the probability that it will be (i) white? (ii) blue? (iii) red?

A box contains tickets numbered 1 to 20.3 tickets are drawn from the box with replacement. The probability that the largest number on the tickets is 7, is

A bag contains 9 discs of which 4 are red, 3 are blue and 2 are yellow. The discs are similar in shape and size. A disc is drawn at random from the bag. Calculate the probability that it will be (i) red, (ii) yellow, (iii) blue, (iv) not blue, (v) either red or blue.

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 black balls are put in the box, the probability of drawing a black ball is now double of what it was before. Find x.

Three numbers are chosedn from 1 to 20 . Find the probability that they are not consecutive

Find the probability that a number selected at random from 1 to 100 is a prime number.

Two numbers are selected from the numbers 1 to 11. If there sum is even find the probability of an event that both numbers are odd.

Three different numbers are selected at random from the set A = (1, 2, 3,...., 10). The probability that the product of two of the numbers is equal to the third is