Use of Adjectiv in a special sentence

[Blacky]

At every table there is a real/really good working computer.

A fast hint would be helpful
Thanks in advance!
Blacky

[Josef Essberger]

At every table there is a really good working computer.

Rationale:
good is an adjective
adjectives are modified by adverbs
really is an adverb (real is an adjective)

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It would be possible to say the following, but I don't think it's what you mean:
At every table there is a real, good, working computer.

The above means something like:
At every table there is a good working computer that is real (not imaginary or fake).

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Finally, you sometimes hear even native speakers of English say that something is "real good", but this is not standard (or "correct") English and I would not recommend its use in an exam. Adjectives are modified by adverbs.

[Blacky]

Thanks a lot for your support and I´m anxious to the solution in the exam

[Blacky]

By the way the song "It´s a real good feeling" presented by D. Hasselhoff is not quite correct