You have an equally likely chance of rolling any value on each of two distinct dice what’s the probability of rolling a sum of either 7 or 9

Answer 1

Ellie

There are 6 possible outcomes on each of the dice, so a total of 6 x 6 = 36 possible outcomes on the two dice together.

How can we get a sum of 7 ? 1+6, 2+5, 3+4, 4+3, 5+2, 6+1 so 6 ways

Sum of 9 ? 3 + 6, 4+5, 5+4, 6+3, 4 ways

So we can get a sum of 7 or 9 in 6+4 = 10 ways

So probability = 10 / 36 = 5/ 18

Mike