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?

844

Given; 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'. 

The logic;

( codes are given as per no. of letters in a word)

So,

1)  ‘birds are flying’ is coded as '536'

birds -> 5

are -> 3

flying -> 6

2)  ‘the nest is big’ is coded as '3423' 

the -> 3

next -> 4

is -> 2

big -> 3

And,

3)  ‘close the door’ is coded as '534'

close -> 5

the -> 3

door -> 4

Similarly,

‘complete your work’ ....?

complete -> 8

your -> 4

work -> 4

Thus, 844 is correct.