Short Answer TypeA bag has 3 red and 7 black balls. One ball is taken out of the bag. Find the probability that it is a
(i) red ball
(ii) black ball.
Cards marked with numbers 2, 3, 4.....61 are
placed in a box and mixed thoroughly. One card is drawn. Find the probability that card drawn in
(i) an even number
(ii) a square number.
1000 families with 2 children mere selected randomly, and the following data were recorded:
|
No. of girls in the family |
No. of families |
|
2 |
500 |
|
1 |
270 |
|
0 |
230 |
Compute the probability of a family, chosen at random having (0 2 girls
(ii) 1 girl
(iii) No girl
Solution not provided.
Ans. 
Three coins are tossed simultaneously 250 times with the following frequencies of different outcomes:
|
Outcome |
Frequency |
|
3 heads |
38 |
|
2 heads |
82 |
|
1 head |
87 |
|
No head |
43 |
If the three coins are simultaneously tossed again, find the probability of
(i) 3 heads
(ii) less than 2 heads
(iii) 2 heads
In a box, there are 9 red, 8 white and 3 black balls. One ball is taken out of the bag. Find the probability that it is
(i) white
(ii) red or black
(iii) not red.
The following table represents the weight of 50 students of a school. A student is selected at random from the school. Find the probability of a student having weight of less than 60 kg.
|
Weight (in kg) |
Number of students |
|
50-55 |
8 |
|
55–60 |
27 |
|
60-65 |
12 |
|
65-70 |
3 |
Given below is the frequency distribution of salary (in र) of 100 workers in a factory:
|
Salary (in र) |
Number of workers |
|
1000–2000 |
10 |
|
2000–3000 |
30 |
|
3000-4000 |
20 |
|
4000-5000 |
40 |
Answer the following questions. How many workers
(i) have salary below र3000?
(ii) have salary between र3000 and र5000?
(iii) from र1000 to र5000?
A die was rolled 100 times and the number of times 6 came up was noted. If the experimental probability calculated from this information is 2/5 then how many times 6 came up? Justify your answer.
Switch
