Question

A dice is rolled once. The following event is described.
A = {Getting 5 or 6}
Which of the following is the complement of A?

• A. {1, 2, 5}
• B. {1, 2, 6}
• C. {1, 2, 3}
• D. {1, 2, 3,4}

Answer 1

The correct option is D {1, 2, 3,4}

When we throw a dice what can happen?? One of the following numbers will appear.
{1, 2,3,4,5 or 6}
So sample space is {1, 2, 3, 4, 5, 6}
Event A is described as throwing a 5 or 6
So
A = {5,6}
Now complement of A = S – A
{1,2,3,4,5,6} - {5, 6}
{1,2,3,4}
Basically complement of A means not A. So everything in sample space except A is complement of A.