Question

if 2 dice are rolled simultaneously then what is probability that the total is a prime number

Answer 1

5/12

the possible primes are 2,3,5,7,11

Answer 2

Answer:

15/72

Step-by-step explanation:

here

there are 5 prime nos possible

2,3,5,7,11

so now

total no. of possibilities is (6*6)*2

bcoz here a no.

for e.g 1 on the first dice can come with 6 other nos. of the second dice at different times

so for 6 nos the total outcomes would be 36

similarly

on the second dice the no. 1 can come with 6 different nos. at different times

so again for 6 nos.the total outcomes would be 36

so now we have total probabilities of 72

now for 2

(1,1) where the first no. shows the no. coming on 1st dice and the second no. shows the no. coming of the 2nd side

for 3

(1,2) ;  (2,1)

for 5

(1, 4) ; ( 4,1) ; (2,3) ; (3,2)

for 7

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

for 11

(5,6); (6,5);

the no. of the above outcomes is 15

hence the probability is 15/72