Given 2 identical spinners divided into four equal parts and numbered 1 2 3 4 what is the probability that the sum of the two spinners will be 3 or 7?

Answer 1

Create a matrix

1 2 3 4

1 2 3 4 5

2 3 4 5 6

3 4 5 6 7

4 5 6 7 8

There is 2/16 chance to get 3, and 2/16 chance to get 7. Therefore, there is 4/16 or 1/4 chance to get either a 3 or a 7.

Answer: 1/4