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- Question
A bag contains 2 red, 3 green and 2 blue balls. Two balls are drawn at random. What is the probability that none of the balls drawn is blue?
Options- A. 10/21
- B. 11/21
- C. 1/2
- D. 2/7
- Correct Answer
- 10/21
ExplanationTotal number of balls = (2 + 3 + 2) = 7.
Let S be the sample space.
Then, n(S) = Number of ways of drawing 2 balls out of 7 = = 21
Let E = Event of drawing 2 balls, none of which is blue.
n(E) = Number of ways of drawing 2 balls out of (2 + 3) balls = = 10
Therefore, P(E) = n(E)/n(S) = 10/ 21.
- 1. A number X is chosen at random from the numbers -3, -2, -1, 0, 1, 2, 3. What is the probability that |X|<2
Options- A. 3/7
- B. 3/4
- C. 4/5
- D. 5/7 Discuss
- 2. In a simultaneous throw of pair of dice. Find the probability of getting the total more than 7.
Options- A. 1/2
- B. 5/12
- C. 7/15
- D. 3/12 Discuss
- 3. Two dice are rolled simultaneously. Find the probability of getting the sum of numbers on the on the two faces divisible by 3 or 4?
Options- A. 3/7
- B. 7/11
- C. 5/9
- D. 6/13 Discuss
- 4. What is the probability that a number is divisible by 4?
Options- A. 2
- B. 1/2
- C. 1/4
- D. 1 Discuss
- 5. The probability that z lies between 0 and 3.01
Options- A. 0.4987
- B. 0.5
- C. 0.9987
- D. 0.1217 Discuss
- 6. An unbiased die is tossed.Find the probability of getting a multiple of 3.
Options- A. 1/3
- B. 1/2
- C. 3/4
- D. 3/2 Discuss
- 7. In a bag which contains 40 balls, there are 18 red balls and some green and blue balls. If two balls are picked up from the bag without replacement, then the probability of the first ball being red and second being green is 3/26. Find the number of blue balls in the bag.
Options- A. 16
- B. 12
- C. 10
- D. 14 Discuss
- 8. There are four hotels in a town. If 3 men check into the hotels in a day then what is the probability that each checks into a different hotel?
Options- A. 1/2
- B. 3/4
- C. 4/7
- D. 3/8 Discuss
- 9. In a race, the odd favour of cars P,Q,R,S are 1:3, 1:4, 1:5 and 1:6 respectively. Find the probability that one of them wins the race.
Options- A. 319/420
- B. 27/111
- C. 114/121
- D. 231/420 Discuss
- 10. 14 persons are seated around a circular table. Find the probability that 3 particular persons always seated together.
Options- A. 11/379
- B. 21/628
- C. 24/625
- D. 26/247 Discuss
Probability problems
Search Results
Correct Answer: 3/7
Explanation:
X can take 7 values.
To get |X|+2) take X={?1,0,1}
=> P(|X|<2) = Favourable CasesTotal Cases = 3/7
Correct Answer: 5/12
Explanation:
Here n(S) = (6 x 6) = 36
Let E = event of getting a total more than 7
= {(2,6),(3,5),(3,6),(4,4),(4,5),(4,6),(5,3),(5,4),(5,5),(5,6),(6,2),(6,3),(6,4),(6,5),(6,6)}
Therefore,P(E) = n(E)/n(S) = 15/36 = 5/12.
Correct Answer: 5/9
Explanation:
Here n(S) = 6 x 6 = 36
E={(1,2),(1,5),(2,1),(2,4),(3,3),(3,6),(4,2),(4,5),(5,1),(5,4),(6,3) ,(6,6),(1,3),(2,2),(2,6),(3,1),(3,5), (4,4),(5,3),(6,2)}
=> n(E)=20
Required Probability n(P) = n(E)/n(S) = 20/36 = 5/9.
Correct Answer: 1/2
Explanation:
Probability is Number of favourable outcomes by total outcomes
Total comes = 2 (Divisible or not)
Favourable = 1 (Divisible)
Hence, probability = 1/2.
Correct Answer: 0.4987
Explanation:
Probability between z = 0 and z = 3.01 is given by
P(0<z<3.01) = P(z<3.01) - P(z<0)
Reading from the z-table, we have
P(z<0) = 0.5
P(z<3.01) = 0.9987
Hence, P(0<z<3.01) = 0.9987 - 0.5 = 0.4987.
Correct Answer: 1/3
Explanation:
Here S = {1,2,3,4,5,6}
Let E be the event of getting the multiple of 3
Then, E = {3,6}
P(E) = n(E)/n(S) = 2/6 = 1/3
Correct Answer: 12
Explanation:
Total balls = 40
Red balls = 18
Let green balls are x
Then, (18/40) × (
Correct Answer: 3/8
Explanation:
Total cases of checking in the hotels = 4 x 4 x 4 = 64 ways.
Cases when 3 men are checking in different hotels = 4×3×2 = 24 ways.
Required probability =24/64 = 3/8
Correct Answer: 319/420
Explanation:
All the events are mutually exclusive hence,
Required probability = P(P)+P(Q)+P(R)+P(S)
=
Correct Answer: 24/625
Explanation:
Total no of ways = (14 ? 1)! = 13!
Number of favorable ways = (12 ? 1)! = 11!
So, required probability = = =
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