Tricky, tricky....., and very slicky.
The total count of tails (assuming everything is occurring as one event and not separated into 2 events), will trend towards a 50% chance: or 1/2 x 8 = 4.
To assume that the preceding coin tosses have any influence on the next coin toss (or total outcome) is known as "Gambler's Fallacy".
This is also related to the Markov Chain: In probability theory and related fields, a Markov Process, named after the Russian mathematician Andrey Markov, is a type of process that satisfies the Markov property, characterized as being "memorylessness".
Now, if you divide the coin tosses into 2 separate events, then the 2 events are additive. So..., 3 + 2 = 5.
Conclusion: both answers (5 and 4) are correct, as it all depends on your interpretation of this type of "trick" question.
Moral of the story:
Become one of the few,
That can think anew,
And develop a different point of view.
And this is what drives innovation.