Question

A pair of dice is rolled. What is the probability of getting a sum of 3?

Answer 1

P(3)=(2/6)(1/6)

P(3)=1/18

This is because the only way to get a sum of 3 is to roll either of two numbers, 1 or 2, on the first die and the only one specific value of 1 or 2 that makes the sum of three on the second die.

Answer 2

There are 6 different numbers on the dice. 1, 2, 3, 4, 5, 6
If there are pairs of dice, that means there are twice as many numbers than on dice.

The possible sum of numbers that equal to 3 are

1 + 2
2 + 1

There would be 36 possibilities in total for pair of dice to get a number.
There are totally 4 possibilities, which makes the probability 4/36, which simplifies into 1/9.