Dice probability problems

Question

A dice is rolled 3 times. What is the probability of getting an even number twice?

Answer 1

there are three scenarios where you could get 2 evens on 3 rolls

EEO (Even, Even, Odd)

EOE (Even, Odd, Even)

OEE (Odd, Even, Even)

for this situation each of those would have a probability of (1/2)^3 = 1/8 of occurring since there is a 1/2 chance that each roll is either even or odd. meaning that the end probability here is

(1/8 + 1/8 + 1/8) = 3/8

so the probability of getting an even number exactly twice in three rolls is 0.375 or 3/8