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- Question
Three unbiased coins are tossed. What is the probability of getting at most two heads?
Options- A. 3/4
- B. 7/8
- C. 1/2
- D. 1/4
- Correct Answer
- 7/8
ExplanationHere S = {TTT, TTH, THT, HTT, THH, HTH, HHT, HHH}
Let E = event of getting at most two heads.
Then E = {TTT, TTH, THT, HTT, THH, HTH, HHT}.
P(E) =n(E)/n(S)=7/8.
- 1. A bag contains 2 red Roses, 4 yellow Roses and 6 pink Roses. Two roses are drawn at random. What is the probability that they are not of same color?
Options- A. 1/6
- B. 2/3
- C. 14/33
- D. 5/6 Discuss
- 2. In a class, 30% of the students offered English, 20% offered Hindi and 10% offered both. If a student is selected at random, what is the probability that he. has offered English or Hindi ?
Options- A. 1/2
- B. 3/4
- C. 4/5
- D. 2/5 Discuss
- 3. If two letters are taken at random from the word HOME, what is the probability that none of the letters would be vowels?
Options- A. 1/6
- B. 1/2
- C. 1/3
- D. 1/4 Discuss
- 4. 8 couples (husband and wife) attend a dance show "Nach Baliye' in a popular TV channel ; A lucky draw in which 4 persons picked up for a prize is held, then the probability that there is atleast one couple will be selected is :
Options- A. 8/39
- B. 15/39
- C. 12/13
- D. None of these Discuss
- 5. One card is drawn at random from a pack of 52 cards. What is the probability that the card drawn is a face card (Jack, Queen and King only)?
Options- A. 3/13
- B. 1/13
- C. 3/52
- D. 9/52 Discuss
- 6. A bag contains 50 tickets numbered 1,2,3,4......50 of which five are drawn at random and arranged in ascending order of magnitude.Find the probability that third drawn ticket is equal to 30.
Options- A. 551/15134
- B. 1/2
- C. 552/15379
- D. 1/9 Discuss
- 7. A speaks truth in 75% of cases and B in 80% of cases. In what percentage of cases are they likely to contradict each other, narrating the same incident
Options- A. 30/100
- B. 35/100
- C. 45/100
- D. 50/100 Discuss
- 8. A bag contains 4 red and 3 black balls. A second bag contains 2 red and 4 black balls. One bag is selected at random. From the selected bag, one ball is drawn. Find the probability that the ball drawn is red.
Options- A. 23/42
- B. 19/42
- C. 7/32
- D. 16/39 Discuss
- 9. There are 26 balls marked with alphabetical order A to Z. What is the probability of selecting vowels listed balls?
Options- A. 1
- B. 21/26
- C. 5/26
- D. 5 Discuss
- 10. A word consists of 9 letters; 5 consonants and 4 vowels.Three letters are choosen at random. What is the probability that more than one vowel will be selected ?
Options- A. 13/42
- B. 17/42
- C. 5/42
- D. 3/14 Discuss
Probability problems
Search Results
Correct Answer: 2/3
Explanation:
Possible outcomes = (RY, YP, PR)
2C1 4C1 + 4C1 6C1 + 6C1 2C1
Required probability = (2C1 4C1 + 4C1 6C1 + 6C1 2C1)/(12C2)
= 8 + 24 + 12/66
= 44/66
= 2/3.
Correct Answer: 2/5
Correct Answer: 1/6
Explanation:
P(first letter is not vowel) =
P(second letter is not vowel) =
So, probability that none of letters would be vowels is =
Correct Answer: 15/39
Explanation:
P( selecting atleast one couple) = 1 - P(selecting none of the couples for the prize)
=
Correct Answer: 3/13
Explanation:
Clearly, there are 52 cards, out of which there are 12 face cards.
P (getting a face card) = 12/52=3/13.
Correct Answer: 551/15134
Explanation:
Total number of elementary events =
Given,third ticket =30
=> first and second should come from tickets numbered 1 to 29 = ways and remaining two in ways.
Therfore,favourable number of events =
Hence,required probability = =551 / 15134
Correct Answer: 35/100
Explanation:
Let A = Event that A speaks the truth
B = Event that B speaks the truth
Then P(A) = 75/100 = 3/4
P(B) = 80/100 = 4/5
P(A-lie) = = 1/4
P(B-lie) = = 1/5
Now, A and B contradict each other =[A lies and B true] or [B true and B lies]
= P(A).P(B-lie) + P(A-lie).P(B)
=
= = 35%
Correct Answer: 19/42
Explanation:
A red ball can be drawn in two mutually exclusive ways
(i) Selecting bag I and then drawing a red ball from it.
(ii) Selecting bag II and then drawing a red ball from it.
Let E1, E2 and A denote the events defined as follows:
E1 = selecting bag I,
E2 = selecting bag II
A = drawing a red ball
Since one of the two bags is selected randomly, therefore
P(E1) = 1/2 and P(E2) = 1/2
Now, = Probability of drawing a red ball when the first bag has been selected = 4/7
= Probability of drawing a red ball when the second bag has been selected = 2/6
Using the law of total probability, we have
P(red ball) = P(A) =
=
Correct Answer: 5/26
Explanation:
We know that,
Total number of balls n(S) = 26
Number of vowels n(E) = 5
Hence, required probability = n(E)/n(S) = 5/26.
Correct Answer: 17/42
Explanation:
3 letters can be choosen out of 9 letters in ways.
More than one vowels ( 2 vowels + 1 consonant or 3 vowels ) can be choosen in ways
Hence,required probability = = 17/42
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