In a certain code BROADEN is written as NQABOFE how is DESKTOP written in that code ?

The word BROADEN is divided into three pars : BRO , A , DEN

I : BRO - NQA

The diagonally opposite element is substituted by its immediate preceding alphabet in the English alphabetical series.

=> B is substituted by A at its diagonally opposite position. Similarly, R is substituted by Q at its diagonally opposite position and O by N.

II : A - B

The middle letter is substituted by its immediate following alphabet in the English alphabetical series.

III : DEN - OFE

The diagonally opposite element is substituted by its immediate following alphabet in the English alphabetical series.

=> D is substituted by E at its diagonally opposite position. Similarly, E is substituted by F at its diagonally opposite position and N by O.

Thus, code for DESKTOP :

DES - RDC

K - L

TOP - QPU

$$\therefore$$ DESKTOP = RDCLQPU