The coin has two sides, one is heads and one is tails. So the probability of getting tails is 1/2, or 50%.
The “circle” divided into 3 parts, ABC...the only vowel is A, B and C are constants. So the probability of getting a vowel is 1/3, or 33.3333.... chance.
The four sided dice has 4 sides, 4 numbers, 1-4. 2 numbers are even. So 2/4 or 1/2 or 50%