Advertisements
Advertisements
प्रश्न
Bulbs are packed in cartons each containing 40 bulbs. Seven hundred cartons were examined for defective bulbs and the results are given in the following table:
| Number of defective bulbs | 0 | 1 | 2 | 3 | 4 | 5 | 6 | more than 6 |
| Frequency | 400 | 180 | 48 | 41 | 18 | 8 | 3 | 2 |
One carton was selected at random. What is the probability that it has
- no defective bulb?
- defective bulbs from 2 to 6?
- defective bulbs less than 4?
उत्तर
Total number of cartons, n(S) = 700
i. Number of cartons which has no defective bulb,
n(E1) = 400
∴ Probability that no defective bulb = `(n(E_1))/(n(S))`
= `400/700`
= `4/7`
Hence, the probability that no defective bulb is `4/7`.
ii. Number of cartons which has defective bulbs from 2 to 6,
n(E2) = 48 + 41 + 18 + 8 + 3 = 118
∴ Probability that the defective bulbs from 2 to 6 = `(n(E_2))/(n(S))`
= `118/700`
= `59/350`
Hence, the probability that the defective bulbs from 2 to 6 is `59/350.`
iii. Number of cartons which has defective bulbs less than 4,
n(E3) = 400 + 180 + 48 + 41 = 669
∴ The probability that the defective bulbs less than 4 = `(n(E_3))/(n(S)) = 669/700`
Hence, the probability that the defective bulbs less than 4 is `669/700.`
APPEARS IN
संबंधित प्रश्न
In a cricket match, a batswoman hits a boundary 6 times out of 30 balls she plays. Find the probability that she did not hit a boundary.
The distance (in km) of 40 engineers from their residence to their place of work were found as follows.
| 5 | 3 | 10 | 20 | 25 | 11 | 13 | 7 | 12 | 31 |
| 19 | 10 | 12 | 17 | 18 | 11 | 32 | 17 | 16 | 2 |
| 7 | 9 | 7 | 8 | 3 | 5 | 12 | 15 | 18 | 3 |
| 12 | 14 | 2 | 9 | 6 | 15 | 15 | 7 | 6 | 12 |
What is the empirical probability that an engineer lives:-
(i) less than 7 km from her place of work?What is the empirical probability that an engineer lives:
(ii) more than or equal to 7 km from her place of work?
(iii) within 1/2 km from her place of work?
| Concentration of SO2 (in ppm) | Number of days (Frequency) |
| 0.00 − 0.04 | 4 |
| 0.04 − 0.08 | 9 |
| 0.08 − 0.12 | 9 |
| 0.12 − 0.16 | 2 |
| 0.16 − 0.20 | 4 |
| 0.20 − 0.24 | 2 |
| Total | 30 |
The above frequency distribution table represents the concentration of sulphur dioxide in the air in parts per million of a certain city for 30 days. Using this table, find the probability of the concentration of sulphur dioxide in the interval 0.12 − 0.16 on any of these days.
The blood groups of 30 students of class IX are recorded as follows:
| A | B | O | O | AB | O | A | O | B | A | O | B | A | O | O |
| A | AB | O | A | A | O | O | AB | B | A | O | B | A | B | O |
(i) A
(ii) B
(iii) AB
(iv) O
Eleven bags of wheat flour, each marked 5 Kg, actually contained the following weights of flour (in kg):
4.97, 5.05, 5.08, 5.03, 5.00, 5.06, 5.08, 4.98, 5.04, 5.07, 5.00
Find the probability that any of these bags chosen at random contains more than 5 kg of flour.
A die is thrown 100 times. If the probability of getting an even number is `2/5` . How many times an odd number is obtained?
In a sample study of 642 people, it was found that 514 people have a high school certificate. If a person is selected at random, the probability that the person has a high school certificate is ______.
In a medical examination of students of a class, the following blood groups are recorded:
| Blood group | A | AB | B | O |
| Number of students | 10 | 13 | 12 | 5 |
A student is selected at random from the class. The probability that he/she has blood group B, is:
Two coins are tossed 1000 times and the outcomes are recorded as below:
| Number of heads | 2 | 1 | 0 |
| Frequency | 200 | 550 | 250 |
Based on this information, the probability for at most one head is
Two dice are thrown simultaneously 500 times. Each time the sum of two numbers appearing on their tops is noted and recorded as given in the following table:
| Sum | Frequency |
| 2 | 14 |
| 3 | 30 |
| 4 | 42 |
| 5 | 55 |
| 6 | 72 |
| 7 | 75 |
| 8 | 70 |
| 9 | 53 |
| 10 | 46 |
| 11 | 28 |
| 12 | 15 |
If the dice are thrown once more, what is the probability of getting a sum
- 3?
- more than 10?
- less than or equal to 5?
- between 8 and 12?
