Ashok delivered the ____________ at his mother’s

Find out the alternative which will replace the question mark?

Vaccination: Disease ∷ Maintenance:?

Drake : Duck : : Wizard : ? 

Select the option that is related to the third letter-cluster in the same way as second letter-cluster is related to the first letter cluster.

If 21 @ 7 = 18 and 43 @ 22 = 68, then 48 @ 49 = '?'.

Select the related number from the given alternatives:

15 : ? :: 14 : 2745

Mercury’ is related to ‘Wednesday’ in the same way as ‘Friday’ is related to:

Given set:  100, 901, 127

Given set:  871, 736, 655