Coding-Decoding

In this type, letters are replaced by numbers. The number can be the letter's position or the sum of positions. For example, 'BAG' could be coded as '217' (positions) or '10' (2+1+7). Some questions use squares of positions, like coding 'B' as '4'.

This concept uses the alphabet in reverse order. 'A' is replaced by 'Z', 'B' by 'Y', and so on. You can find the reverse letter by subtracting the forward position from 27. If the word 'ACT' is coded as 'Z X G', it uses reverse pairs.

This involves shifting letters forward or backward by a specific number. For example, if 'MAN' is coded as 'NBO', each letter moved forward by +1. The shift can be constant (+2, +2, +2) or increasing (+1, +2, +3). Always check the gap between the original and coded letter.

Number assignment means assigning numerical values to letters. Usually, A=1, B=2, C=3, and so on. The code might involve mathematical operations on these numbers. For example, each number could be multiplied by two. Then, 'ABC' (123) would be coded as '246'. Understand that the formula applied can be different. It's crucial to check every possible calculation. Remember that the examiner might try to confuse the students. They might use squares of the alphabet's numbers.

In reverse coding, the order of letters in a word is reversed. For instance, 'INDIA' becomes 'AIDNI'. The reversed word may be further coded using other methods. Be aware that only a part of the word could be reversed. Or, specific letters can be reversed, not the whole word. Therefore, be ready for unexpected variations in reverse coding exercises.