What should come in place of '?' in the given

Select the option in which the numbers are not related in the same way as are the number of the following set.

(9, 18, 81)

Select the set of numbers that is similar to the following set.

(12, 187, 15)

Three of the following four number-pairs are alike in a certain way and one is different. Find the odd one out.

Find the one which does not belong to that group?

Three out of the following four words are similar in meaning. Find the word that is different from the rest.

Four of the following five are alike in a certain way based on a group, which among the following does not belong to that group?

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

Select the letter cluster which does not belong to the same group from the given alternatives.

Find the odd one out.

Find the odd one out: