英语数学题,有关概率的independent event

题目

英语数学题,有关概率的independent event
Consider the following experiments and events:
(i)A fair coin is tossed 5 times.E is the event that the first toss is heads.F is the event that the third toss is tails.
(ii)A fair coin is tossed 3 times.E is the event that the first toss is heads.F is the event that heads is tossed at least once.
(iii)Two cards are drawn,without replacement,from a standard deck.E is the event that the first card is a heart.F is the event that the second card is black.
In which of these are E and F independent events?
A.(i) only
B.(ii) only
C.(iii) only
D.(i) and (ii) only
E.(i) and (iii) only

答案

(i) and (iii) only.
That is that E is the answer.