A committee of three members is to be formed from the following individuals: X, Y, Z, W, and V. The selection criteria are: 1) X and Y cannot be on the committee together. 2) Z must be included if W is included. Which of the following groups is a valid selection?
If '?' represents multiplication, '?' represents division, '?' represents addition, and '?' represents subtraction, what is the value of 4 ? 3 ? 2 ? 5 ? 1?