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
