Question

Hannah rolls two number cubes with the numbers 5,5,5,3,6,6on each.What i the probability that she rolled two numbers with an even sum?

Answer 1

There are 7 ways for it to be and odd sum. Can you figure out the even sums?

Answer 2

The only way she can roll an odd sum is if she gets one odd number and one even number.

There are 4 odd numbers and 2 even numbers. The probability of rolling an odd number is 4/6 = 2/3. The probability of rolling an even number is 2/6 = 1/3.

The probability of rolling an odd sum is 2/3 * 1/3 * 2 = 4/9. (multiplied by 2 because it can be odd number then even OR even number then odd)

So, the probability of rolling an even sum is 1 - 4/9 = 5/9