Advertisements
Advertisements
प्रश्न
A dice is rolled 600 times and the occurrence of the outcomes 1, 2, 3, 4, 5 and 6 are given below:
| Outcome | 1 | 2 | 3 | 4 | 5 | 6 |
| Frequency | 200 | 30 | 120 | 100 | 50 | 100 |
The probability of getting a prime number is
विकल्प
`1/3`
`2/3`
`49/60`
`39/125`
उत्तर
The total number of trials is 600.
Let A be the event of getting a prime number (2, 3 and5).
The number of times A happens is 30+120+50 = 200 .
Remember the empirical or experimental or observed frequency approach to probability.
If n be the total number of trials of an experiment and A is an event associated to it such that A happens in m-trials. Then the empirical probability of happening of event A is denoted by P (A) and is given by
` P (A) = m/n`
Therefore, we have
` P (A) = 200/600`
`= 1/3`
APPEARS IN
संबंधित प्रश्न
An organization selected 2400 families at random and surveyed them to determine a relationship between income level and the number of vehicles in a family. The information gathered is listed in the table below:-
|
Monthly income (in Rs.) |
Vehicles per family | |||
| 0 | 1 | 2 | Above 2 | |
| Less than 7000 | 10 | 160 | 25 | 0 |
| 7000 – 10000 | 0 | 305 | 27 | 2 |
| 10000 – 13000 | 1 | 535 | 29 | 1 |
| 13000 – 16000 | 2 | 469 | 59 | 25 |
| 16000 or more | 1 | 579 | 82 | 88 |
Suppose a family is chosen, find the probability that the family chosen is
(i) earning Rs 10000 − 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 vehicles.
(v) owning not more than 1 vehicle.
The percentage of attendance of different classes in a year in a school is given below:
| Class: | X | IX | VIII | VII | VI | V |
| Attendance: | 30 | 62 | 85 | 92 | 76 | 55 |
What is the probability that the class attendance is more than 75%?
In a football match, Ronaldo makes 4 goals from 10 penalty kicks. The probability of converting a penalty kick into a goal by Ronaldo, is
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:
A company selected 4000 households at random and surveyed them to find out a relationship between income level and the number of television sets in a home. The information so obtained is listed in the following table:
| Monthly income (in Rs) |
Number of Television/household | |||
| 0 | 1 | 2 | Above 2 | |
| < 10000 | 20 | 80 | 10 | 0 |
| 10000 – 14999 | 10 | 240 | 60 | 0 |
| 15000 – 19999 | 0 | 380 | 120 | 30 |
| 20000 – 24999 | 0 | 520 | 370 | 80 |
| 25000 and above | 0 | 1100 | 760 | 220 |
Find the probability:
- of a household earning Rs 10000 – Rs 14999 per year and having exactly one television.
- of a household earning Rs 25000 and more per year and owning 2 televisions.
- of a household not having any television.
A company selected 4000 households at random and surveyed them to find out a relationship between income level and the number of television sets in a home. The information so obtained is listed in the following table:
| Monthly income (in Rs) |
Number of Television/household | |||
| 0 | 1 | 2 | Above 2 | |
| < 10000 | 20 | 80 | 10 | 0 |
| 10000 – 14999 | 10 | 240 | 60 | 0 |
| 15000 – 19999 | 0 | 380 | 120 | 30 |
| 20000 – 24999 | 0 | 520 | 370 | 80 |
| 25000 and above | 0 | 1100 | 760 | 220 |
Find the probability of a household earning Rs 25000 and more per year and owning 2 televisions.
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 between 8 and 12?
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 under 40 years
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 under 60 but over 39 years
