Discussion
Home ‣ Aptitude ‣ Probability Comments
- Question
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 10 - B.
2 5 - C.
2 7 - D.
5 7 - Correct Answer
-
2 7
ExplanationP (getting a prize) = 10 = 10 = 2 . (10 + 25) 35 7 - 1. 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.
2 7 - D.
5 7
Discuss
- 2. Three unbiased coins are tossed. What is the probability of getting at most two heads?
Options- A. 3/4
- B. 1/4
- C. 3/8
- D. 7/8 Discuss
- 3. In a box, there are 8 red, 7 blue and 6 green balls. One ball is picked up randomly. What is the probability that it is neither red nor green?
Options- A.
1 3 - B.
3 4 - C.
7 19 - D.
8 21 - E.
9 21
Discuss
- 4. A bag contains 6 black and 8 white balls. One ball is drawn at random. What is the probability that the ball drawn is white?
Options- A.
3 4 - B.
4 7 - C.
1 8 - D.
3 7
Discuss
- 5. From a pack of 52 cards, two cards are drawn together at random. What is the probability of both the cards being kings?
Options- A.
1 15 - B.
25 57 - C.
35 256 - D.
1 221
Discuss
- 6.
The banker's discount on a certain sum due 2 years hence is 11 of the true discount. 10 The rate percent is:
Options- A. 11%
- B. 10%
- C. 5%
- D. 5.5% Discuss
- 7. The banker's discount on Rs. 1600 at 15% per annum is the same as true discount on Rs. 1680 for the same time and at the same rate. The time is:
Options- A. 3 months
- B. 4 months
- C. 6 months
- D. 8 months Discuss
- 8. The banker's discount on a bill due 4 months hence at 15% is Rs. 420. The true discount is:
Options- A. Rs. 400
- B. Rs. 360
- C. Rs. 480
- D. Rs. 320 Discuss
- 9. The present worth of a sum due sometime hence is Rs. 576 and the banker's gain is Rs. 16. The true discount is:
Options- A. Rs. 36
- B. Rs. 72
- C. Rs. 48
- D. Rs. 96 Discuss
- 10. The banker's discount on a sum of money for 1½ years is Rs. 558 and the true discount on the same sum for 2 years is Rs. 600. The rate percent is:
Options- A. 10%
- B. 13%
- C. 12%
- D. 15% Discuss
Probability problems
Search Results
Correct Answer:
| 10 |
| 21 |
Explanation:
Total 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 | |||
| = 7C2 ` | ||||
|
||||
| = 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. | |||
| = 5C2 | ||||
|
||||
| = 10. |
| ∴ P(E) = | n(E) | = | 10 | . |
| n(S) | 21 |
Correct Answer: 7/8
Explanation:
Here 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) | = | 7 | . |
| n(S) | 8 |
Correct Answer:
| 1 |
| 3 |
Explanation:
Total number of balls = (8 + 7 + 6) = 21.
| Let E | = event that the ball drawn is neither red nor green |
| = event that the ball drawn is blue. |
∴ n(E) = 7.
| ∴ P(E) = | n(E) | = | 7 | = | 1 | . |
| n(S) | 21 | 3 |
Correct Answer:
| 4 |
| 7 |
Explanation:
Let number of balls = (6 + 8) = 14.
Number of white balls = 8.
| P (drawing a white ball) = | 8 | = | 4 | . |
| 14 | 7 |
Correct Answer:
| 1 |
| 221 |
Explanation:
Let S be the sample space.
| Then, n(S) = 52C2 = | (52 x 51) | = 1326. |
| (2 x 1) |
Let E = event of getting 2 kings out of 4.
| ∴ n(E) = 4C2 = | (4 x 3) | = 6. |
| (2 x 1) |
| ∴ P(E) = | n(E) | = | 6 | = | 1 | . |
| n(S) | 1326 | 221 |
Correct Answer: 5%
Explanation:
Let T.D. be Re. 1.
| Then, B.D. = Rs. | 11 | = Rs. 1.10. |
| 10 |
| ∴ Sum = Rs. | ❨ | 1.10 x 1 | ❩ | = Rs. | ❨ | 110 | ❩ | = Rs. 11. |
| 1.10 - 1 | 10 |
∴ S.I. on Rs. 11 for 2 years is Rs. 1.10
| ∴ Rate = | ❨ | 100 x 1.10 | ❩% | = 5%. |
| 11 x 2 |
Correct Answer: 4 months
Explanation:
S.I. on Rs. 1600 = T.D. on Rs. 1680.
∴ Rs. 1600 is the P.W. of Rs. 1680, i.e., Rs. 80 is on Rs. 1600 at 15%.
| ∴ Time = | ❨ | 100 x 80 | ❩year | = | 1 | year = 4 months. |
| 1600 x 15 | 3 |
Correct Answer: Rs. 400
Explanation:
| T.D. |
|
|||||||||||
|
||||||||||||
|
||||||||||||
| = Rs. 400. |
Correct Answer: Rs. 96
Explanation:
T.D. = √P.W. x B.G. = √576 x 16 = 96.
Correct Answer: 12%
Explanation:
| B.D. for 3⁄2 years | = Rs. 558. | |||||||
| B.D. for 2 years |
|
|||||||
| = Rs. 744 |
T.D. for 2 years = Rs. 600.
| ∴ Sum = | B.D. x T.D. | = Rs. | ❨ | 744 x 600 | ❩ | = Rs. 3100. |
| B.D. - T.D | 144 |
Thus, Rs. 744 is S.I. on Rs. 3100 for 2 years.
| ∴ Rate = | ❨ | 100 x 744 | ❩% | = 12% |
| 3100 x 2 |
Comments
There are no comments.More in Aptitude:
Programming
Copyright ©CuriousTab. All rights reserved.