Which SQL operator is used to search for a pattern in a

In each of the following questions select the related letter/word/figure/number from the given alternatives.

JRH : ? : : KOV : 51 

Find the missing number.

What number should come in the place of question mark?

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

LHX: OEA : : PFT : ?

In the following question, a series is given with one term missing. Choose the correct alternative from the given ones that will complete the series.

Find the missing number.

In the following question, select the missing number from the given alternatives.

45, 15, 60, 75, 135, ?

What will come in the place of question mark?

Find the missing term in the given series: