Select the most appropriate direct form of the given

Three of the following four figure pairs are alike in a certain way and than form a group. Which is the one that does not belong to that group?

In a certain code language,

‘A + B’ means ‘A is the son of B’,

‘A – B’ means ‘A is the sister of B’,

On which of the following days skating is trained?

X says, "Y” is my mother's only daughter." How Is Y related to X? 

Six persons, Vinay, Madhav, Nilesh, Sagar, Arvind, Rajesh, are standing in two rows facing towards each other such that three persons are in a row.

What should come in place of the question mark (?) in the given series?

115 97 81 67 55 ?

Four of the following five are alike in a certain way and hence form a group. Which is the one that does not belong to that group?

Which letter-cluster will replace the question mark (?) to complete the given series?

GOWB, MVEK, SCMT, ?, EQCL

MASTER : TSAMRE :: SMILES : LIMSSE :: FLIMSY : ?

Three of the following number pairs are alike in some manner and hence form a group. Which number pair does NOT belong to that group?