Question

A pair of dice is rolled.

What is the probability of getting a sum greater than 3?

and

a sum less than 10?

Answer 1

well, a sum less that 3 can be 2. And the no. of ways to get the sum as 2 is only one --> (1,1)

so, one favorable outcome.

sample space = 36.

so what's the probability?

Answer 2

(2,1) ?

Answer 3

or (1,2) ?

Answer 4

so is it 35/36? since 1 outcome is less then 3

Answer 5

Oh am sorry, we need a sum *greater* than 3. Misread it. :/

Yes, you were going right, so we include (1,2) and (2,1) with(1,10 in the set of "unfavorable outcomes".
so, favorable outcomes = 36 - 3 = 33

hence probability = 33/36

Answer 6

As for the second part, for a sum 'lesser' than 10, we use the same method to find out the no. of favorable outcomes.

Outcomes with sum equal to or greater than 10 = (4,6), (6,4), (5,5), (5,6), (6,5) and (6,6).
= 6

so no of outcomes with sum less than 10 = 36 - 6 = 30

Hence probability = 30/36 = 5/6

Answer 7

@monroe17