1. chAPTER-1 CODING AND DECODING
Process to transmitting the information in the form of codes or signals between the sender or receiver without knowing the third person.
CODING- Converting the piece of information into another form of representation through signals.
DECODING- It is the reverse process of converting the coded information back into original form understandable by a receiver.
Forward Order Position(left to right)
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

2. Backward Order Position(right to left) A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Backward position of any letter= 27- forward order position of that position ex- Backward position of A = 27- forward position of A = =26 Opposite Latters some of opposite latters is equal to 27. A 1 Z 26 B 2 Y 25 C 3 X 24 D 4 W 23 E 5 V 22 F 6 U 21 G 7 T 20 H 8 S 19 I 9
R 18 J 10 Q 17 K 11 P 16 L 12 O 15 M 13 N 14

3. Opposite position of any latter= 27- corresponding position of that position eg- opposite position of A= 27- corresponding position of A = = = Z Pair of opposite letters- A-Z (AaZa) B-Y(By) C-X(Six) D-W(Dew) E-V(Evening) F-U(Future) G-T(GT Road) H-S(High school) I-R(Indian Railway) J-Q(Jungle Queen) K-P(Kanpur) L-O(Love) M-N(Man)

4. There are different type of question ask in SSC EXAMINATION
There are different type of question ask in SSC EXAMINATION. Q- If in coded language ‘BRINJAL’ is written as ‘LANJNIRB’, then how will ‘LADYFINGER’ be written in that code? (1) RNEGIFYDL (2) RINEGIFYDAL (3) REGNIFYDAL (4) REGNIFYDYAL (5) ADLYIFNGER