What does 'in no time' mean?

[Sonies]

English Language Proficiency Tests, Advanced Level

ESL/EFL Test #627 "Prepositional Phrases - On, In, Under and Out (1)", question 1

Don't worry about a thing. You'll feel better ......... no time. You look better already and the flu doesn't usually last more than a couple of days.

(a) on
(b) in
(c) under
(d) out

English Language Proficiency Tests, Advanced Level

ESL/EFL Test #627 "Prepositional Phrases - On, In, Under and Out (1)", answer 1

Don't worry about a thing. You'll feel better in no time. You look better already and the flu doesn't usually last more than a couple of days.

Correct answer: (b) in

Your answer was: incorrect
Don't worry about a thing. You'll feel better out no time. You look better already and the flu doesn't usually last more than a couple of days.
_________________________

please explain the meaning of the phrase ' no time '

[Torsten]

The phrase is 'in no time' and it means very soon.

TOEFL listening lectures: What is the problem with the concept of brain lateralization?