I believe the problem definition has a mistype. With the current definition, we have P(X < 4) = \frac{1}{2} (e.g. 1,2,3) and P(X > 4) = \frac{1}{3} (e.g. 5,6). Under this definition, you are unable to arrive at any of the solutions in the multiple choice. When I went to the forums to see if I was doing something wrong, all the mentor responses implied that it’s actually P( X \ge 4) = \frac{1}{2}. With P(x \ge 4), I was able to arrive at the solution since my error stemmed from the problem definition and not my understanding.

Please update the question to be “If the result is greater than or equal to 4”