In a multiple choice question, there are five alternative answers of which one or more than one are correct. A candidate will get marks on the question, if he ticks all the correct answers. If he decides to tick answer all random, then the least number of choices should he be allowed, so that the probability of his getting marks on the question exceeds (1)/(8) is

We saw in this chapter that there are four main stakeholders when it comes to forests and wildlife. Which among these should have the authority to decide the management of forest produce? Why do you think so?

Five persons entered the lift cabin on the ground floor of a 8 floor house. Suppose each of them can leave the cabin independently at any floor beginning with the first. The total number of ways in which each of the five person can leave the cabin at any one of the 7 floor, is

Outcomes of which of the following experiments are equally likely? 1. Getting a digit 1, 2, 3, 4, 5 or 6 when a die is rolled. Selecting a different colour ball from a bag of 5 red balls, 4 blue balls and 1 black ball. Winning in a game of carrom. Units place of a two digit number selected may be 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9. Selecting a different colour ball from a bag of 10 red balls, 10 blue balls and 10 black balls. Raining on a particular day of July

A box contains N coins, m of which are fair and the rest are biased. The probability of getting a head when a fair coin is tossed is 1/2 while it is 2/3 when a biased coin is tossed. A coin is drawn from the box at random and is tossed twice. The first time it shows head and the second time it shows tail. What is the probability that the coin drawn is fair?

Consider the random experiment of tossing dice. If number obtained on it is multiple of 3 then toss dice again, and if any other number is obtained toss a coin. Find probability of an event that coin shows tail given that at least once number 2 comes up.

6 balls marked as 1,2,3,4,5 and 6 are kept in a box. Two players A and B start to take out 1 ball at a time from the box one after another without replacing the ball till the game is over. The number marked on the ball is added each time to the previous sum to get the sum of numbers marked on the balls taken out. If this sum is even, then 1 point is given to the players. the first player to get 2 points is declared winner. at the start of the game, the sum is 0. if A starts to take out the ball, find the number of ways in which the game can be won.

Consider the experiment of throwing a die, if a multiple of 3 comes up, throw the die again and if any other number comes, toss a coin. Find the conditional probabilityof the event 'the coin shows a tail', given that at least one die shows a 3'.

The minimum number of times a fair coin needs to be tossed, so that the probability of getting at least two heads is at least 0.96 is :

Suppose you have two coins which appear identical in your pocket. You know that, one is fair and one is 2-headed. If you take one out, toss it and get a head, what is the probability that it was a fair coin ?