Advertisements
Advertisements
प्रश्न
Three coins are tossed once. Find the probability of getting
- 3 heads
- 2 heads
- at least 2 heads
- at most 2 heads
- no head
- 3 tails
- exactly two tails
- no tail
- atmost two tails.
उत्तर
If 3 coins are tossed, then the sample space of the experiment is
S = {HHH, HHT, HTH, THH, TTH, THT, HTT, TTT}
Total possible outcomes = 8
(i) Three heads {HHH} can appear in one way.
So the probability of getting 3 heads = `1/8`
(ii) There are three ways of getting 2 heads or 2 heads 1 tail, HHT, HTH, THH.
Total possible outcomes = 8
Probability of 2 heads appearing = `3/8`
(iii) To get a minimum of 2 heads, 2 heads 1 tail or 3 heads will occur
∴ A minimum of 2 heads can appear in four ways, HHT, HTH, THH, HHH.
Hence, the probability of minimum 2 heads appearing = `4/8`
= `1/2`
(iv) Maximum 2 heads will appear as follows.
(a) No head or three tails
(b) One head 2 tails
(c) 2 heads 1 tail
This {TIT, HTT, THT, TTH, HHT, HTH, THH} can appear in seven ways.
Total possible outcomes = 8
∴ Probability of maximum 2 heads appearing = `7/8`
(v) No head appearing means three tails appearing, which can happen in one way (TTT).
Total possible outcomes = 8
Hence, the probability of no head appearing = `1/8`
(vi) Three tails can appear in one way (TTT).
Probability of three tails appearing = `1/8`
(vii) Actually 2 tails (TTH, THT, HTT) can be obtained in three ways.
Total possible outcomes = 8
∴ Probability of two tails appearing = `3/8`
(viii) No tails means all three heads appear, so (HHH) can happen in only 1 way.
Total possible outcomes = 8
Probability of no tails appearing = `1/8`
(ix) Maximum two tails appearing
⇒ All three tails do not appear.
Probability of all three tails appearing = `1/8`
∴ Probability of maximum two tails appearing = 1 – (Probability of all three tails appearing)
= `1 - 1/8`
= `7/8`
APPEARS IN
संबंधित प्रश्न
A card is selected from a pack of 52 cards.
- How many points are there in the sample space?
- Calculate the probability that the card is an ace of spades.
- Calculate the probability that the card is
- an ace
- black card.
There are four men and six women on the city council. If one council member is selected for a committee at random, how likely is it that it is a woman?
In a lottery, person chooses six different natural numbers at random from 1 to 20, and if these six numbers match with the six numbers already fixed by the lottery committee, he wins the prize. What is the probability of winning the prize in the game? [Hint: order of the numbers is not important.]
Fill in the blank in following table:
| P(A) | P(B) | P(A ∩ B) | P(A ∪ B) |
| `1/3` | `1/5` | `1/15` | .... |
Fill in the blank in following table:
| P(A) | P(B) | P(A ∩ B) | P(A ∪ B) |
| 0.35 | ... | 0.25 | 0.6 |
4 cards are drawn from a well-shuffled deck of 52 cards. What is the probability of obtaining 3 diamonds and one spade?
From the employees of a company, 5 persons are selected to represent them in the managing committee of the company. Particulars of five persons are as follows:
| S. No. | Name | Sex | Age in years |
| 1. | Harish | M | 30 |
| 2. | Rohan | M | 33 |
| 3. | Sheetal | F | 46 |
| 4. | Alis | F | 28 |
| 5. | Salim | M | 41 |
A person is selected at random from this group to act as a spokesperson. What is the probability that the spokesperson will be either male or over 35 years?
The number lock of a suitcase has 4 wheels, each labelled with ten digits i.e., from 0 to 9. The lock opens with a sequence of four digits with no repeats. What is the probability of a person getting the right sequence to open the suitcase?
Two unbiased dice are thrown. Find the probability that the sum of the numbers obtained on the two dice is neither a multiple of 2 nor a multiple of 3
A bag contains 8 red, 3 white and 9 blue balls. If three balls are drawn at random, determine the probability that all the three balls are blue balls
Which of the cannot be valid assignment of probability for elementary events or outcomes of sample space S = {w1, w2, w3, w4, w5, w6, w7}:
| Elementary events: | w1 | w2 | w3 | w4 | w5 | w6 | w7 |
| (i) | 0.1 | 0.01 | 0.05 | 0.03 | 0.01 | 0.2 | 0.6 |
In a single throw of three dice, find the probability of getting the same number on all the three dice.
A box contains 100 bulbs, 20 of which are defective. 10 bulbs are selected for inspection. Find the probability that: all 10 are defective
A box contains 100 bulbs, 20 of which are defective. 10 bulbs are selected for inspection. Find the probability that all 10 are good
A box contains 100 bulbs, 20 of which are defective. 10 bulbs are selected for inspection. Find the probability that none is defective
An urn contains twenty white slips of paper numbered from 1 through 20, ten red slips of paper numbered from 1 through 10, forty yellow slips of paper numbered from 1 through 40, and ten blue slips of paper numbered from 1 through 10. If these 80 slips of paper are thoroughly shuffled so that each slip has the same probability of being drawn. Find the probabilities of drawing a slip of paper that is numbered 1, 2, 3, 4 or 5
In a leap year the probability of having 53 Sundays or 53 Mondays is ______.
Three-digit numbers are formed using the digits 0, 2, 4, 6, 8. A number is chosen at random out of these numbers. What is the probability that this number has the same digits?
Three squares of chessboard are selected at random. The probability of getting 2 squares of one colour and other of a different colour is ______.
Six new employees, two of whom are married to each other, are to be assigned six desks that are lined up in a row. If the assignment of employees to desks is made randomly, what is the probability that the married couple will have nonadjacent desks?
Four candidates A, B, C, D have applied for the assignment to coach a school cricket team. If A is twice as likely to be selected as B, and B and C are given about the same chance of being selected, while C is twice as likely to be selected as D, what are the probabilities that A will not be selected?
The accompanying Venn diagram shows three events, A, B, and C, and also the probabilities of the various intersections (for instance, P(A ∩ B) = .07). Determine `P(B ∩ barC)`
The accompanying Venn diagram shows three events, A, B, and C, and also the probabilities of the various intersections (for instance, P(A ∩ B) = .07). Determine `P(A ∩ barB)`
A bag contains 8 red and 5 white balls. Three balls are drawn at random. Find the probability that all the three balls are white
A bag contains 8 red and 5 white balls. Three balls are drawn at random. Find the probability that all the three balls are red
If the letters of the word ASSASSINATION are arranged at random. Find the probability that two I’s and two N’s come together
If the letters of the word ASSASSINATION are arranged at random. Find the probability that no two A’s are coming together
In a non-leap year, the probability of having 53 tuesdays or 53 wednesdays is ______.
Seven persons are to be seated in a row. The probability that two particular persons sit next to each other is ______.
Without repetition of the numbers, four-digit numbers are formed with the numbers 0, 2, 3, 5. The probability of such a number divisible by 5 is ______.
If the probabilities for A to fail in an examination is 0.2 and that for B is 0.3, then the probability that either A or B fails is ______.
The probability that a student will pass his examination is 0.73, the probability of the student getting a compartment is 0.13, and the probability that the student will either pass or get compartment is 0.96.
If A and B are two candidates seeking admission in an engineering College. The probability that A is selected is .5 and the probability that both A and B are selected is at most .3. Is it possible that the probability of B getting selected is 0.7?
The probability that the home team will win an upcoming football game is 0.77, the probability that it will tie the game is 0.08, and the probability that it will lose the game is ______.
A box contains 10 red marbles, 20 blue marbles and 30 green marbles. 5 marbles are drawn from the box, what is the probability that atleast one will be green?
If 4-digit numbers greater than 5,000 are randomly formed from the digits 0, 1, 3, 5, and 7, what is the probability of forming a number divisible by 5 when, the repetition of digits is not allowed?
