Find odd in the following

Three of the following four letters are alike in a certain way and one is different. Pick the odd one out.

Directions : In each of the following questions, four words have been given out of which three are alike in a certain way and one is different. Choose out the odd one.

Choose the odd word/letters/number pair from the given alternatives.

In the following question, select the odd word/letters from the given alternatives.

Three of the following four words are alike in a certain way and one is different. Select the odd word.

The odd word is

Choose the related word/letters/number from the given alternatives.
 36 : 6 : : 441 : ?