Verbal Reasoning - Mental Ability Questions

In a certain code language, "DIAMOND" is written as "4895064" and "GAME" is written as "7953". How is "MANGO" written in that code language?

If A = 1, E = 5, then HEAR = ?

If 4!4 = 4, 14!2 = 8 and 10!18 = 14, then find the value of 2!6 = ?

If 70*10 = -7, 50*5 = -10 and 10*5 = -2, then find the value of 80*1 = ?

A series is given, with one word missing. Choose the correct alternative from the given ones that will complete the series.

employ, oyster, errors, ornate, tennis, ?

A series is given, with one term missing. Choose the correct alternative from the given ones that will complete the series.
ZYX, VUT, QPO, MLK, HGF, ?

In the following question, select the related number from the given alternatives.
65 : 82 : : 145 : ?

Select the related number from the given alternatives.
77 : 84 :: 121 : ?