Bunuel wrote:

What is the probability that the sum of two rolled dice will equal a prime number?

(A) 1/3

(B) 5/36

(C) 2/9

(D) 13/36

(E) 5/12

Kudos for correct solution.

Lets find out how many nos. equals to prime number when we add two rolled dice from 1 to 6

So no. of ways are -

1 , 1

1 , 2

2 , 1

1 , 4

4 , 1

1 , 6

6 , 1

2 , 3

3 , 2

2 , 5

5 , 2

3 , 4

4 , 3

6 , 5

5 , 6

Therefore we have 15 possibilities (favourable events)

Total possible events = 6 * 6 = 36 (since one dice contains 6 possible ways)

Therefore

probability = \frac{15}{36} = \frac{5}{12}
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