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- Question
A bag contains 3 black, 4 white and 5 red balls. One ball is drawn at random. Find the probability that it is either black or red ball:
Options- A. 2/3
- B. 1/4
- C. 5/12
- D. 1/2
- Correct Answer
- 2/3
ExplanationP(black ball)=3/12
P(red ball)=5/12
P(black or red)=3/12+5/12=2/3
- 1. In a lottery, there are 10 prizes and 25 blanks. A lottery is drawn at random. What is the probability of getting a prize ?
Options- A. 1/7
- B. 2/7
- C. 3/7
- D. 2/5 Discuss
- 2. Find the probability of selecting 2 woman when four persons are choosen at random from a group of 3 men, 2 woman and 4 children.
Options- A. 1/5
- B. 1/7
- C. 1/6
- D. 1/9 Discuss
- 3. The odds favouring the event of a person hitting a target are 3 to 5. The odds against the event of another person hitting the target are 3 to 2. If each of them fire once at the target, find the probability that both of them hit the target.
Options- A. 1/20
- B. 4/20
- C. 1/20
- D. 3/20 Discuss
- 4. Find the probability that it is either white or red ball when,one ball is drawn at random in a bag that contains 3 black,4 white and 5 red balls
Options- A. 0.5
- B. 0.75
- C. 0.25
- D. 0.8 Discuss
- 5. From well shuffled standard pack of 52 playing cards,one card is drawn. What is the probability that it is either a red card or black card?
Options- A. 1/2
- B. 3/4
- C. 1
- D. 1/3 Discuss
- 6. What is the probability that a leap year selected at random, will contain 53 sundays?
Options- A. 1/7
- B. 1/3
- C. 2/7
- D. 4/7 Discuss
- 7. A father said his son , " I was as old as you are at present at the time of your birth. " If the father age is 38 now, the son age 5 years back was :
Options- A. 14
- B. 19
- C. 33
- D. 38 Discuss
- 8. In 10 years, A will be twice as old as B was 10 years ago. If A is now 9 years older than B, the present age of B is :
Options- A. 19
- B. 29
- C. 39
- D. 49 Discuss
- 9. The total age of A and B is 12 years more than the total age of B and C. C is how many years younger than A ?
Options- A. 12
- B. 13
- C. 14
- D. 15 Discuss
- 10. The age of a man is 4 times his son. Five years ago, the man was nine times old as his son was at that time. The present age of man is?
Options- A. 24 years
- B. 32 years
- C. 40 years
- D. 44 years Discuss
Probability problems
Search Results
Correct Answer: 2/7
Explanation:
P(getting prize) = 10/ (10 + 25) =2/7
Correct Answer: 1/6
Explanation:
Out of 9 persons,4 can be choosen in ways =126.
Favourable events for given condition = = 21.
So,required probability = 21/126 =1/6.
Correct Answer: 3/20
Explanation:
Let A be the event of first person hitting the target,
Let B be the event of Second person hitting a target.
Since both events are independent and both will hit the target so,
Correct Answer: 0.75
Explanation:
P(red ball) = 5/12
P(white ball) = 4/12
P(red or white ball) = 5/12 + 4/12 = 3/4 = 0.75
Correct Answer: 1
Explanation:
P(red cards)=26/52
P(black cards)=26/52
P(red or black cards)=26/52+26/52=1
Correct Answer: 2/7
Explanation:
In a leap year,there are 366 days=52 weeks and 2 days
Remaining favourable 2 days can be sunday and monday or saturday and sunday
Exhaustive number of cases =7
Favourable number of cases =2
So,required probability=2/7
Correct Answer: 14
Explanation:
Let the son's present age be x years .Then, (38 - x) = x => x= 19.
Son's age 5 years back = (19 - 5) = 14 years
Correct Answer: 39
Explanation:
Let B's present age = x years. Then, A's present age = (x + 9) years.
(x + 9) + 10 = 2(x - 10)
=> x + 19 = 2x - 20
=> x =39.
Correct Answer: 12
Correct Answer: 32 years
Explanation:
Let the son's be x years, then father's age = 4x years ∴ (4x - 5) = 9(x - 5) ⇒ 5x = 40 ⇒ x = 8 ∴ Present age of the man = 32 years
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