Firstly, remember all the alphabets and numerical values are provided to each and every letter accordingly.
Here is a small logic like "How to remember all the numerical values".
Consider,
E's numerical value is 5
J's numerical value is 10
O's numerical value is 15
T's numerical value is 20
Y's numerical value is 25
So based on these numerical values, the letters near to it is easily obtained. This rule is also known as EJOTY rule.
Example: What is the numerical value of L?
L is near to letter J.
So, if J is 10 then L numerical value is 12.
Also, need to know letters from left and letters from right. Left direction is from A to Z and Right direction is from Z to A.
The questions are based in the form of: from left, from right, left of - from the left, right of - from right, right of - from left, left of - from the right, in original alphabets - if first half is written in reverse order(by reversing left becomes right and right becomes left) and need to find numerical letter from left and from right, in original alphabets - if the second half is written in reverse order and need to find the numerical value letter from left and right.
Example 1: Which letter is the 22nd from left?
From the above rule, T's numerical value is 20. So, 22nd letter is V.
Example 2: Which letter is fifteenth from right?
First need to convert the numerical value into from left i.e. from 27 - 15 = 12
By EJOTY rule, 12th letter is L.
Note:
While converting, why the given value is to be subtracted from 27 and not 26?
Because if needed to find first letter from right, 26 - 1 = 25 i.e. y but actual letter is Z. Therefore, 27 is used while subtracting and not 26.