K comes before L
N comes before O
S comes before T
T comes before U
R comes before S

This way KNSTR is correct option

Like M E A T-----> T E A M

Similarly BALE will be written as EALB

Move two letter backward (-2)
if we move two letter back after H it comes F.
if we move two letter back after K it comes I.
if we move two letter back after I it comes R.
if we move two letter back after G it comes E.

Every single word is coded here like T ? X ,A ? E etc...
We have to use every word coded in TABLECLOTH in HOTEL as well.
H ? T
O ? I
T ? X
E ? A
L ? R

Move +2,+3,+4 forward for first 3 letters
Move -2,-3,-4 backward for last 3 letters

C +2 = E
A + 3 = D
S + 4 = W
K - 2 = I
E - 3 = B
T - 4 = P

So The answer is EDWIBP

Interchange the alphabets of odd pair of words, and keep even pair as it is.

C O ? OC
N T ? NT
I N ? NI
U O ? UO
U S ? SU

CONTINUOUS ? OCNTNIUOSU

If P means #,A means %,C means $ and E means@
So,
P ? #
E ? @
A ? %
C ? $
E ? @

So the code for PEACE will be #@%$@

From question
DELHI ? 73541 ---(i)
CALCUTTA ? 82589662 ...(ii)

from (i) and (ii)
C ? 8,
A ? 2,
L ? 5,
I ? 1,
C ? 8,
U ? 9,
T ? 6

So the code for CALICUT will be 8251896.

Split the word into two parts and append the first part at the end of second.

From question it is clear that we need to make 2 words from word APTITUDE where first word should have first 5 alphabets and remaining 3 alphabets will be part of 2nd word.

APTITUDE ? APTIT + UDE ? UDEAPTIT

So the code for APTITUDE is UDEAPTIT.

From question it is clear that each alphabet has a code based on their alphabetical order. For example a=1, b=2 ....z=26.

by going through options
l ? 12
o ? 15
v ? 22
e ? 5

so code for 1215225 is love.