Question

When two dice are rolled, how do you find the probability of getting a sum of 6 or 7?

Answer 1

Probability of getting a sum of 6 or 7 is `11/36`.

Explanation:

When two dices are rolled , there are `6xx6=36` outcomes of the type `(x,y)`, where `x` is outcome of first dice and `y` is outcome of second dice. As both `x` and `y` can take values from `1` to `6`, there are total `36` outcomes.

Of these the outcomes `(1,5)`, `(2,4)`, `(3,3)`, `(4,2)` and `(5,1)` denote we have a got a sum of `6` and the outcomes `(1,6)`, `(2,5)`, `(3,4)`, `(4,3)`, `(5,2)` and `(6,1)` denote we have a got a sum of `7`.

Hence there are `11` outcomes (of the total of `36` outcomes) which give us the desired output.

Hence probability of getting a sum of 6 or 7 is `11/36`.