In a certain code language, ‘birds are flying’ is coded as '536', ‘the nest is big’ is coded as '3423' and ‘close the door’ is coded as '534'. How will ‘complete your work’ be coded in that language? 

The logic followed here is : The number of letter in a word ⇒ Code 

Given :

• ‘birds are flying’ is coded as '536'

​birds → It is a five letters word, therefore the code is ⇒ 5

are → It is a three letters word, therefore the code is ⇒ 3

flying → It is a six letters word, therefore the code is ⇒ 6

• ‘the nest is big’ is coded as '3423'

​the → It is a three letters word, therefore the code is ⇒ 3

nest → It is a four letters word, therefore the code is ⇒ 4

is → It is a two letters word, therefore the code is ⇒ 2

big → It is a three letters word, therefore the code is ⇒ 3

And,

• ‘close the door’ is coded as '534'

​close → It is a five letters word, therefore the code is ⇒ 5

the → It is a three letters word, therefore the code is ⇒ 3

door → It is a four letters word, therefore the code is ⇒ 4

Similarly,

• ‘complete your work’ is coded as 

​​complete → It is a eight letters word, therefore the code is ⇒ 8

your ​close → It is a four letters word, therefore the code is ⇒ 4

work ​close → It is a five letters word, therefore the code is ⇒ 4

Thus, code for ‘complete your work’ is '844'.

Hence, "844" is the correct answer.