Which of the following pairs is correctly

Find the missing number.

. 

Select the missing number from the given responses.

Select the related word/letters/number from the given alternatives.

LHX: OEA : : PFT : ?

Find the missing number.

20, 30, 42, 56, 72, ?

Select the option that is related to the third number in the same way as the second number is related to the first number.

15 : 5 :: 26 : (?)

Select the number which can be placed in the column of question mark sign.

Study the given pattern carefully and select the number that can replace the question mark [?] in it.

Find the missing number.

15 Select the number from among the given options that can replace the question mark (?) in the following series.

24, 48, 51, 204, 209, ?