Which country recently hosted the first-ever

Find the ODD one out from the given options.

Four words have been given out of which three are alike in some manner, while one is different. Choose the odd one.

Find the odd word pair out from the given options.

Four numbers have been given out of which three are alike in some manner, while one is different. Choose the odd one.

Find the one which does not belong to that group?

Find the odd one out from the given alternatives.

Five letter-clusters have been given out of which four are alike in some manner and one is different. Select the one that is different.

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

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.