Question

I play a game in which two dice are thrown together. I win if the product of the two numbers appearing on their tops is odd or a multiple of 5. The probability of my winning is : 

(1) 1/3

(2) 5/12

(3) 7/18

(4) 1/4

Answer 1

Correct option (2) 5/12

Explanation:

P(odd) = {1,3,5,9, 15, 25}

P(multiple of 5) = {5, 10, 15, 20, 25,30}

(1,1), (1,5), (5,1)

(1,3), (3,1), (3,3)

(5,3), (3,5) 

(5,5), (2,5), (5,2) 

(4,5),(5,4),(6,5), (5,6)

P(E) = 15/36 = 5/12