Four unit squares are chosen at random on a chessboard. What is the probability that three of them are of one colour and fourth is of opposite colour?

Which letter is such that the difference of its integer-code with the integer-code of T is the same as that between the integer-codes of N and S?

What is the probability that a non-leap year has 53 Fridays?

Organising a party requires a lot of effort. In a buffet salad party, the host had 4 differentvegetables for salads. How many different salads can a guest make from the four vegetables -lettuce, cucumber, carrot, and mushrooms, if even a single vegetable is a salad ?

Three unbiased coins are tossed. What is the probability of getting at most two heads?

In a game there are 70 people in which 40 are boys and 30 are girls, out of which 10 people are selected at random. One from the total group, thus selected is selected as a leader at random. What is the probability that the person, chosen as the leader is a boy?

An urn contains 6red, 5 blue and 2 green marbles. If three marbles are picked at random, what is the probability that at least one is blue?

A and B play a game where each is asked to select a number from 1 to 5. If the two numbers match, both of them win a prize. The probability that they will not win a prize in a single trial is:

Two cards are drawn  together from a pack of 52 cards .The probability that one is a spade and one is a heart ,is

In a simultaneous throw of two coins he probability of getting at least one head is