Question

Two dice are thrown simultaneously. Let A be the event of getting sum less than 4 and B be the event of getting sum not more than 4. Find set “A and not B”.

(a) {(1,1), (1,2), (2,1)}

(b) {}

(c) {(1,1), (1,2), (1,3), (2,1), (2,2), (3,1)}

(d) {(1,3), (2,2), (3,1)}

This question was addressed to me in homework.

My query is from Probability in chapter Probability of Mathematics – Class 11

Answer 1

Correct choice is (b) {}

The explanation is: A = {(1,1), (1,2), (2,1)}

B= {(1,1), (1,2), (1,3), (2,1), (2,2), (3,1)}

“A and not B” contains elements which are in A but not in B.

So, A and not B = {}.