(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Toss a pair of fair dice, one in red and the other is blue. Define the events

A={Red dice showing 1 or 2 or 3}

B={Red dice showing 3 or 4 or 5}

C={The sum of points on the two dice equals 9}

Are the 3 events pairwise independent? mutually independent? Justify your answer.

2. Relevant equations

Events A and B are independent if and only if P(A intersection B) = P(A) x P(B)

3. The attempt at a solution

P(A)=P(B)=1/2

P(C)=4/36=1/9 (Since 9=3+6=4+5=5+4=6+3)

P(A intersection B) = P(Red *dice* showing 3) = 1/6 *should be die*

P(A intersection C) = 1/36 (Since the only possible combination that results in 9 is 3+6)

Likewise, P(B intersection C) = 3/36 = 1/12

It can be seen that P(A intersection B) ≠ P(A) x P(B) so A and B are not independent. The same conclusion can be made for A and C, B and C.

Therefore, A, B, C are neither pairwise independent nor mutually independent.

Above is my first try at the problem but I'm not sure if it's correct or not. Would appreciate it if someone would help me clarify this, thanks!

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# Homework Help: Independent events

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