Answer: Choice B
==============================
Explanation:
The probability of some event is always between 0 and 1. The 0 referring to the idea its impossible to happen (ie "0 percent chance") and 1 refers to "absolute certainty (ie "100 percent chance").
In short, [tex]0 \le p \le 1[/tex] which means "p is between 0 and 1 inclusive"
With this in mind, we can rule out choice A because the 1.05 is larger than 1. Similarly, we can rule out choice D because of the negative probability values.
-------
It's now down between B or C
Add up the values in the bottom row for each table
for choice B, we have: 0.4+0.15+0.25+0.2 = 1
for choice C, we have: 0.2+0.35+0.15+0.25 = 0.95
-------
Choice B is the answer because all probability values are between 0 and 1, and the sum of adding them all up leads to 1
Choice C is ruled out because the sum is not 1, even though all individual probabilities are in the right interval.
