Question : How is 'DATE' written in the code language ?

Statements :
I. DEAR is written as $#@? in that code.
II. TREAT is written as %?#@% in that code.
III. TEAR is written as %#@? in that code.

Explanation:-

Observing I, II and III, we find that similar letters have similar code symbols at the corresponding places in the code. So, this is direct-coding.
Thus, to find the code for DATE, we need the code for D which can be obtained from I only (i.e. $.) and the codes for A, T and E which can be obtained either from II or III (@, # and % respectively).