A special die has a number on each face. The sums of the opposite faces are all equal. Five of the numbers are 5,6,9,11, and 14. What number is on the sixth face?

The missing number is 15.

Step-by-step explanation:

The sum of the opposite faces is 20, because 14 + 6 = 20 and 11 + 9 = 20, so we just need to find the answer to the equation

5 + x = 20

Solving for x, we have

x = 20-5

x = 15.

Therefore, the missing number is 15.