Question

Two dice are rolled. Find the prob. of getting a sum greater than 9 or a sum less than 4 or a sum of 7.

Answer 1

Solution:

total number of possibilities while rolling two dies = 6 * 6 = 36

number of possibilities of getting greater than 9 = 6

they are :

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

number of possibilities of getting less than 4 = 3

they are :

(1,1),(1,2),(2,1)

number of possibilities of getting 7 =6

they are ,

(3,4),(4,3),(2,5),(5,2),(1,6),(6,1)

total number of possibilities of getting a sum greater than 9 or a sum less than 4 or a sum of 7 = 6+3+6

= 15

probability of getting a sum greater than 9 or a sum less than 4 or a sum of 7.= 15 / 36 = 0.4166