The mean of the probability distribution of the number obtained on throwing a die having 1 on three faces, 2 on two faces, and 5 on one face is:

Given:
1 appears on 3 faces
2 appears on 2 faces
5 appears on 1 face
Total outcomes = 6

Formula used:
Mean (Expected Value) = (value × probability) summed over all outcomes
Solution:
Mean = (1 × 3/6) + (2 × 2/6) + (5 × 1/6)
$$=\frac 36 + \frac 46 + \frac56$$​ = $$\frac{12}{2}$$​ = 2
Correct answer is (b)