Which of the following property of soil is not

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 word which does not belong to the same group from the given alternatives.

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

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

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

Four number-pairs have been given, out of which three are alike in some manner and one is different. Select the number-pair that is different.

Find the odd one out from the following options. 

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

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