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.
In Q.5, Exercise 14.2, you were asked to prepare a frequency distribution table, regarding 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
In Q.1, Exercise 14.2, you were asked to prepare a frequency distribution table regarding the blood groups of 30 students of a class. Use this table to determine the probability that a student of this class, selected at random, has blood group AB.
A and B are the only two outcomes of an event. Probability P(A) = 0.72 then what will be the probability P(B) and why?
A survey of 500 families was conducted to know their opinion about a particular detergent powder. If 375 families liked the detergent powder and the remaining families disliked it, find the probability that a family chosen at random
(i) likes the detergent powder
(ii) does not like it.
1500 families with 2 children were released randomly and the following data was recorded:
No. of girls |
No. of families |
0 1 2 |
211 814 475 |
If a family is chosen at random, find the probability that it has
(i) at most one girl
(ii) at least one girl
Total number of families = 1500
(i) at most one girl means 0 girl or 1 girl.
∴ Number of families which have at most one girl
= 211 +814= 1015
∴Probability that it has at most one girl
(ii) at least one girl means 1 girls or 2 girls.
∴ Number of families which have at least one girl
= 814 + 475 = 1289
∴ Probability that it has at least one girl
Out of the past 250 consecutive days, its weather forecasts were correct 175 times.
(i) What is the probability that on a given day it was correct?
(ii) What is the probability that it was not correct on a given day?
A die is rolled 25 times and outcomes are recorded as under:
Outcomes |
Frequency |
1 |
9 |
2 |
4 |
3 |
5 |
4 |
6 |
5 |
1 |
6 |
0 |
It is thrown one more time. Find the probability of getting
(a) an even number
(b) a multiple of 3
(c) a prime number.
A bag contains 5 red balls, 8 white balls, 4 green balls and 7 black balls. If one ball is drawn at random, find the probability that it is
(i) black
(ii) not green.
Cards marked with numbers 2 to 101 are placed in a box and mixed thoroughly. One card is drawn from this box. Find the probability that the number on the card is
(a) a number less than 14
(b) a number which is a perfect square
(c) a prime number less than 20.