1. A bag-I contains four cards numbered 1, 3, 5 and 7 respectively. Another bag-II contains three cards numbered 2, 4 and 6 respectively. A card is drawn at random from each bag. Find the probability that the sum of two cards drawn is 9.
All outcomes = 12 ⇒ |
2. A bag contains 7 white, 3 red and 4 black balls. A ball is drawn at random. Find the probability that it is a red or a black ball.
Hint: Total number of possible outcomes = 7 + 3 + 4 = 14. Out of 14 possible outcomes, there are 7 favourable outcomes (3 red and 4 black) i.e. there are 7 balls that are either red or black. ∴ Required probability = P(a red or a black ball) = (7/14)= (1/2) |
3. In a single throw of two dice, find the probability of getting a total of 8.
∴ Favourable outcomes are : (2, 6), (3, 5), (4, 4), (5, 3), (6, 2) i.e. 5 outcomes are favourable. |
4. One card is drawn from a well-shuffled deck of 52 cards. Find the probability of getting a face card.
Hint: 52 cards are divided into 4 suits of 13 cards each. Kings, queen and jacks are called face-cards. ∴ Total number of face cards = 3 × 4 = 12 ∴ Favourable outcomes = 12 ⇒ Required probability = (12/52)= (3/13) |
5. Two unbiased coins are tossed once. What is the probability of getting exactly one head?
Hint: In a throw of two coins, the total number of possible outcomes = 22 = 4 [namely : (H, H), (H, T), (T, H) and (T, T)]. For the event of getting exactly one head (i.e. no tail). ⇒ Favourable outcomes are (H, T) and (T, H) i.e., 2 ⇒ Required probability = (2/4)= (1/2) |
1. What is probability and how is it related to mathematics? |
2. How is probability calculated for an event? |
3. What is the difference between theoretical probability and experimental probability? |
4. How can probability be used in everyday life? |
5. What are the fundamental principles of probability? |
|
Explore Courses for Class 9 exam
|