Verbal Reasoning - Mental Ability Questions

In the following question, which one set of letters when sequentially placed at the gaps in the given letter series shall complete it?
c_e_cd_f_d_f

In a code language, if LUCK is written as L2U1C3K1, then what is the last digit for the code for XEROX in that same language?

If 1∆-5=5, 4∆7=-28 and -1∆-3=-3, then find the value of 8∆-8 =?

If 37*14 = 17,
69*33 = 34,
91*125 = 72
then what should 28*56 = ?

A series is given,with one term missing. Choose amongst the given responses choose the meaningful one

CUS, DVT, EWU, ____

Nikhil is father in law of Tara. Tara is the wife of Rahul. How is Rahul's brother related to Nikhil?

In the following question, select the related word pair from the given alternatives.

Nest : Bird : : ? : ?

If RESEARCH is $#!#%$&@ then SCARE is