NCERT Solution: Probability
Total numbers of bags = 11
Numbers of bags containing more than 5 kg of flour = 7
Required probability = 7/11
A study was conducted to find out the concentration of sulphur dioxide in the air in parts per million (ppm) of a certain city. The frequency distribution of the data obtained for 30 days is as follows:
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 |
Using this table, find the probability of the concentration of sulphur dioxide in the interval 0.12 - 0.16 on any of these days.
Number days for which the concentration of sulphur dioxide was in the interval of 0.12 - 0.16 = 2
Total number of days = 30
Hence, required probability, P = 2/30
= 1/15
The blood groups of 30 students of class VIII are given in the following frequency distribution table:
Blood group |
Number of students |
A |
9 |
B |
6 |
AB |
3 |
O |
12 |
Total |
30 |
Use this table to determine the probability that a student of this class, selected at random, has blood group AB.
Number of students having blood group AB = 3
Total number of students = 30
Hence, required probability, P = 3/30
= 1 / 10