Refer to Example 13. (i) Complete the following table: (ii) A student argues that ‘there are 11 possible outcomes 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12. Therefore, each of them has a probability 1/11. Do you agree with this argument? Justify your answer.
Answers
Refer to Example 13.
(i) Complete the following table:
Probability of an event
= no. of possible outcomes / total no of favorable outcomes
No. of possible outcomes to get the sum as 2 = (1, 1)
No. of possible outcomes to get the sum as 3 = (2, 1) and (1,2)
No. of possible outcomes to get the sum as 4 = (3, 1),(1, 3),(2, 2)
No. of possible outcomes to get the sum as 5 = (4, 1), (1,4), (2, 3), (3, 2)
No. of possible outcomes to get the sum as 6 = (5, 1), (1, 5), (2, 4), (4, 2),
(3,3)
No. of possible outcomes to get the sum as 7 = (6, 1), (1, 6), (2, 5), (5, 2),
(3,4), (4,3)
No. of possible outcomes to get the sum as 8 = (6,2),(2,6),(3,5),(5,3),
(4,4)
No. of possible outcomes to get the sum as 9 = (3, 6), (6, 3), (4, 5), (5, 4)
No. of possible outcomes to get the sum as 10 = (4, 6), (6, 4), (5, 5)
No. of possible outcomes to get the sum as 11 = (5, 6), (6, 5)
No. of possible outcomes to get the sum as 12 = (6, 6)
Event Probability
2 1/36
3 2/36
4 3/36
5 4/36
6 5/36
7 6/36
8 5/36
9 4/36
10 3/36
11 2/36
12 1/36
(ii) A student argues that ‘there are 11 possible outcomes 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12.
Probability of each of these sums will not be as these sums are not equally likely.