A bag contains 4 red balls and 5 blue balls. Two balls are drawn at random without replacement. If the first ball drawn is blue, what is the probability the second ball is also blue?

Let A and B be two events such that \(\rm P\left( \overline{A\cup B} \right)=\frac{1}{6}\), \(\rm P\left( A\cap B \right)=\frac{1}{4}\) and \(\rm P\left( \overline{A} \right)=\frac{1}{4}\), where A̅ is the complementary event of A. Then A and B are:

At a car park there are 100 vehicles, 60 of which are cars, 30 are vans and the remainder are Lorries. If every vehicle is equally likely to leave, find the probability of car leaving second if either a lorry or van had left first. 

(a) 3/10 

(b) 20/33 

(c) 1/10 

(d) 3/5

A dice is rolled and at the same time 2 coins are tossed, what is the probability of getting a number more than 3 and atleast one head?

A forest contains 20 elks, of which 5 are captured, tagged and then released. A certain time later, 4 of the 20 elks are captured. What is the probability that 2 of these 4 have been tagged? What assumptions are made?