Advertisements
Advertisements
प्रश्न
A recent survey found that the ages of workers in a factory is distributed as follows:
| Age (in years) | 20 – 29 | 30 – 39 | 40 – 49 | 50 – 59 | 60 and above |
| Number of workers | 38 | 27 | 86 | 46 | 3 |
If a person is selected at random, find the probability that the person is:
- 40 years or more
- under 40 years
- having age from 30 to 39 years
- under 60 but over 39 years
उत्तर
Total number of workers in a factory,
n(S) = 38 + 27 + 86 + 46 + 3 = 200
i. Number of persons selected at the age of 40 years or more,
n(E1) = 86 + 46 + 3 = 135
∴ Probability that the persons selected at the age of 40 years or more,
`P(E_1) = (n(E_1))/(n(S))`
= `135/200`
= 0.675
Hence, the probability that the person selected at the age of 40 years or more is 0.675.
ii. Number of persons selected under the age of 40 years
n(E2) = 38 + 27 = 65
∴ Probability that the persons selected under the age of 40 years,
`P(E_2) = (n(E_2))/(n(S))`
= `65/200`
= 0.325
Hence, the probability that the persons selected under the age of 40 years is 0.325.
iii. Number of persons selected having age from 30 to 39 years,
n(E3) = 27
∴ Probability that the person selected having age from 30 to 39 years,
`P(E_3) = (n(E_3))/(n(S))`
= `27/200`
= 0.135
Hence, the probability that the person selected having age from 30 to 39 years is 0.135.
iv. Number of persons selected having age under 60 but over 39 years,
n(E4) = 86 + 46 = 132
∴ Probability that the person selected having age under 60 but over 39 years,
`P(E_4) = (n(E_4))/(n(S))`
= `132/200`
= 0.66
Hence, the probability that the person selected having age under 60 but over 39 years is 0.66.
APPEARS IN
संबंधित प्रश्न
In a particular section of Class IX, 40 students were asked about the months of their birth and the following graph was prepared for the data so obtained:-
Find the probability that a student of the class was born in August.
To know the opinion of the students about the subject statistics, a survey of 200 students was conducted. The data is recorded in the following table.
| Opinion | Number of students |
| like | 135 |
| dislike | 65 |
Find the probability that a student chosen at random
(i) likes statistics, (ii) does not like it
In a cricket match, a batsman hits a boundary 6 times out of 30 balls he plays.
(i) he hits boundary
(ii) he does not hit a boundary.
Following table shows the birth month of 40 students of class IX.
| Jan | Feb | March | April | May | June | July | Aug | Sept | Oct | Nov | Dec |
| 3 | 4 | 2 | 2 | 5 | 1 | 2 | 5 | 3 | 4 | 4 | 4 |
Given below is the frequency distribution table regarding the concentration of sulphur dioxide in the air in parts per million of a certain city for 30 days.
| Conc. of SO2 | 0.00-0.04 | 0.04-0.08 | 0.08-0.12 | 0.12-0.16 | 0.16-0.20 | 0.20-0.24 |
| No. days: | 4 | 8 | 9 | 2 | 4 | 3 |
Find the probability of concentration of sulphur dioxide in the interval 0.12-0.16 on any of these days.
A company selected 2400 families at random and survey them to determine a relationship between income level and the number of vehicles in a home. The information gathered is listed in the table below:
| Monthly income: (in Rs) |
Vehicles per family | |||
| 0 | 1 | 2 | Above 2 | |
| Less than 7000 7000-10000 10000-13000 13000-16000 16000 or more |
10 0 1 2 1 |
160 305 535 469 579 |
25 27 29 29 82 |
0 2 1 25 88 |
If a family is chosen, find the probability that family is:
(i) earning Rs10000-13000 per month and owning exactly 2 vehicles.
(ii) earning Rs 16000 or more per month and owning exactly 1 vehicle.
(iii) earning less than Rs 7000 per month and does not own any vehicle.
(iv) earning Rs 13000-16000 per month and owning more than 2 vehicle.
(v) owning not more than 1 vehicle
(vi) owning at least one vehicle.
In a survey of 364 children aged 19 – 36 months, it was found that 91 liked to eat potato chips. If a child is selected at random, the probability that he/she does not like to eat potato chips 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:
Over the past 200 working days, the number of defective parts produced by a machine is given in the following table:
| Number of defective parts |
0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 |
| Days | 50 | 32 | 22 | 18 | 12 | 12 | 10 | 10 | 10 | 8 | 6 | 6 | 2 | 2 |
Determine the probability that tomorrow’s output will have atleast one defective part
A recent survey found that the ages of workers in a factory is distributed as follows:
| Age (in years) | 20 – 29 | 30 – 39 | 40 – 49 | 50 – 59 | 60 and above |
| Number of workers | 38 | 27 | 86 | 46 | 3 |
If a person is selected at random, find the probability that the person is having age from 30 to 39 years
