Question

A pair of dice is thrown and sum of the numbers on the days to comes to be 7 what is the probability that the numbers 3 has come on one of the dice

(a) 1/9

(b) 1/3

(c)1/4

(d)none​

Answer 1

Answer:

Option ( b ).

Step-by-step explanation:

For the number of favourable outcomes :

When a pair of dice is thrown, first one may have any number between ( and including ) 1 and 6, and the same condition for the second dice..

So, here instead of writing all possible pairs, just write the pairs if natural numbers( between & including 1 & 6 ) who give a sum of 7.

Possible ( & required ) outcomes are ( 1 , 6 ) , ( 2 , 5 ) , ( 3 , 4 ) , ( 4 , 3 ) , ( 5 , 2 ) , ( 6 , 1 ), and the same for second dice.

Here, possible( = required ) outcomes = 6 and outcomes having 3 are 2.

Therefore,

Number of favourable outcomes = ( outcomes having 3 ) / total possibilities

= > 2 / 6

= > 1 / 3