The document covers basic probability concepts relevant for GRE quant preparation, including examples of probability calculations. It presents various scenarios such as coin tosses, drawing cards, and seating arrangements to illustrate the application of these concepts. Additionally, it hints at upcoming content on laws of probability.

2. • We learn the basic concepts of Probability learnt in Classes 10 and 11.
• These are useful in the GRE QUANT section as well.

4. Question 1
A coin is tossed twice. What is the probability of getting at least one tail?

7. Question 2
If odds in favour of an event are 2:1, what is the probability of the event?

9. Question 3
If 6 persons sit in a row, what is the probability that A and B are sitting on adjacent
seats?

13. Question 4
2 cards are drawn at random from a well shuffled pack of 52 cards. Find the probability
that one is red and the other black.

17. Question 5
In a group there are 3 men and 2 women. 3 persons are selected at random. Find the
probability that the group consists of 1 man and 2 women or 2 men and 1 woman.

20. Question 6
Out of 8 points in a plane, 5 are collinear. Find the probability that 3 points selected at
random will form a triangle.

23. 5 𝐶2
× 3 𝐶1

26. o We have learnt the basic concepts of Probability.
o Odds in favour of or odds against.

27. Watch out for the next video on Laws of Probability.