To solve the logical reasoning questions,there is no special formula.
You have to use your mind,according to the situation of questions.
1.B2CD …. BCD4,B5CD,BC6D
Because the letters are same,concentrate the number series,which is simple 2 3 4 5 6 and follow each letter in order.
Here you can see the 1st letter is an increasing alphabet order and 2nd letter is a decreasing alphabet order.so
Here you can see the only the middle letter is an increasing order ie (letter +1).
Here middle letter is same ie constant. 1st and 3rd letter are simply in increasing order starting with Q & R respectively.
5.if SUMAN can written as NUMAS the KUMAR can be written as.
Here 1st and last letter are exchanged so
6.If ABC can be written as 123 then XYZ can be written as
ABC values are assigned according to the integer value starting to 1 so
Answer ,XYZ can be written as 24 25 26
1st letter is an increasing order,2nd &3rd same letter increasing with (letter+1).
Here,there are two series 1st series is an increasing order and 2nd is decreasing order.
Here ‘a’ is an odd series and ‘b’ is an even series.
Three letters are taken in reverse mode of alphabetical letter.