a pair of dice is rolled once find the probability of getting a sum divisible by 3 or 2

Hi Shivani dear, as we roll a pair of dice then in sample pace we have 36 chances
Let A be the event having number divisible by 3
So A {3,6,9,12)) 
Let B be the event having number divisible by 2
So B {2,4,6,8,10,12}
AnB = {6,12}
So P(A) = 4/36 = 1/9
And P(B) = 6/36 = 1/6
P(AnB) = 2/36 = 1/18
We need P(AUB) = p(A) + P(B) - P(AnB) = 1/9 + 1/6 - 1/18 = (2 + 3 - 1)/18 = 4/18 = 2/9

  • 1
What are you looking for?