What's the term for the security measure that hides the

Which of the following terms will replace the question mark (?) in the given series?

ABC, ZYX, BCD, YXW, CDE,?

If 'ABACUS' is coded as 'CEEARO’, how will ‘EFFORT’ be coded as in the same code? 

Which of the following sequences represents the correct English dictionary order of the following words?

1. Approach

2. Approval

Which two numbers (not digits) should be interchanged to make the given equation correct?

Select the letter-cluster from among the given option that can replace the question mark (?) in the following series.

Statements:

A < C <  F;  G > H = F < K < L

Conclusions:

I).  G > K

II). K ≥ G

Answer the questions based on the information given below.