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

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

52 ∶ 91 : : 72 ∶ ?

A. 138

B. 109

C. 98

D. 126

Sol:

The logic followed here is :-

Product of extremes = Product of means

⇒ a : b = c : d

⇒ ad = bc

Given 52 ∶ 91 : : 72 ∶ ?

Consider 52 ∶ 91 : : 72 ∶ X

⇒ 52X = 91 × 72

⇒ 52X = 6552

=>x=6552/52

=>x=126