In a certain code SUBSTANCE is written as RATRUFDOB How is TENTHOUSE written in that code ?

The word SUBSTANCE is divided into three parts : SUBS , T , ANCE

I : SUBS - RATR

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

=> S is substituted by R at its diagonally opposite position. Similarly, U is substituted by T at its diagonally opposite position and similarly B & S by A and R.

II : T - U

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

III : ANCE - FDOB

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

=> A is substituted by B at its diagonally opposite position. Similarly N is substituted by O at its diagonally opposite position and similarly C & E by D and F.

Thus, code for TENTHOUSE :

TENT - SMDS

H - I

OUSE - FTVP

$$\therefore$$ TENTHOUSE - SMDSIFTVP