Q6 of 134 Page 32

A die is thrown twice. Each time the number appearing on it is recorded. Describe the following events:

(i) A = Both numbers are odd.


(ii) B = Both numbers are even


(iii) C = sum of the numbers is less than 6.


Also, find A B, A B, A C, A C. Which pairs of events are mutually exclusive.

Given: A dice is thrown twice. And each time number appearing on it is recorded.


To Find: Describe the given events.


Explanation: when the dice is thrown twice then the number of sample spaces are 62 = 36


Now,


The possibility both odd numbers are:


A = {(1, 1), (1, 3), (1, 5), (3, 1), (3, 3), (3, 5), (5, 1), (5, 3), (5, 5)}


Since, Possibility of both even numbers are:


B = {(2, 2)(2, 4)(2, 6)(4, 2)(4, 4)(4, 6)(6, 2)(6, 4)(6, 6)}


And, Possible outcome of sum of the numbers is less than 6


C = {(1, 1)(1, 2)(1, 3)(1, 4)(2, 1)(2, 2)(2, 3)(3, 1)(3, 2)(4, 1)}


Therefore,


(AՍB) = {(1, 1), (1, 3), (1, 5), (3, 1), (3, 3), (3, 5), (5, 1), (5, 3), (5, 5) (2, 2)(2, 4)(2, 6)(4, 2)(4, 4)(4, 6)(6, 2)(6, 4)(6, 6)}


(AՌB) = {Փ}


(AUC) = {(1, 1), (1, 3), (1, 5), (3, 1), (3, 3), (3, 5), (5, 1), (5, 3), (5, 5) (1, 2)(1, 4)(2, 1)(2, 2)(2, 3)(3, 1)(3, 2)(4, 1)}


(AՌC) = {(1, 1)(1, 3)(3, 1)}


Hence, (AՌB) = Փ and (AՌC)≠Փ, A and B are mutually exclusive, but A and C are not.


More from this chapter

All 134 →
4

In a single throw of a die describe the following events:

(i) A = Getting a number less than 7


(ii) B = Getting a number greater than 7


(iii) C = Getting a multiple of 3


(iv) D = Getting a number less than 4


(v) E = Getting an even number greater than 4.


(vi) F = Getting a number not less than 3.


Also, find A B, A B, B C, E F, D F and .

5

Three coins are tossed. Describe

(i) two events A and B which are mutually exclusive.


(ii) three events A, B and C which are mutually exclusive and exhaustive.


(iii) two events A and B which are not mutually exclusive.


(iv) two events A and B which are mutually exclusive but not exhaustive.

7

Two dice are thrown. The events A, B, C, D, E and F are describes as follows.

A = Getting an even number on the first die.


B. Getting an odd number on the first die.


C = Getting at most 5 as sum of the numbers on the two dice.


D = Getting the sum of the numbers on the dice greater than 5 but less than 10.


E = Getting at least 10 as the sum of the numbers on the dice.


F = Getting an odd number on one of the dice.


(i) Describe the following events: A and B, B or C, B and C, A and E, A or F, A and F


(ii) State true or false:


(a) A and B are mutually exclusive.


(b) A and B are mutually exclusive and exhaustive events


(c) A and C are mutually exclusive events


(d) C and D are mutually exclusive and exhaustive events


(e) C, d and E are mutually exclusive and exhaustive events


(f) A’ and B’ are mutually exclusive events


(g) A, B, F are mutually exclusive and exhaustive events

8

The numbers 1, 2, 3 and 4 are written separately on four slips of paper. The slips are then put in a box and mixed thoroughly. A person draws two slips from the box, one after the other, without replacement. Describe the following events:

A = The number on the first slip is larger than the one on the second slip.


B = The number on the second slip is greater than 2


C = The sum of the numbers on the two slips is 6 or 7


D = The number on the second slips is twice that on the first slip.


Which pair (s) of events is (are) mutually exclusive?