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) Â red ball
(ii) Â black ball.Â
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) Â an even number
(ii) Â 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) Â 1 girl
(iii) Â No girl
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) Â 3 heads
(ii) Â less than 2 heads
(iii) Â 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) Â white
(ii) Â red or black
(iii) Â not red.Â
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.Â
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