In a proportion the product of 1^st and 4^th terms is 40 and that of 2^nd and 3^rd terms is 2.5x. Then the value of x is.

A. 16

B. 26

C. 75

D. 90

Answer: Option A

Solution(By Examveda Team)

Product of 1^st and 4^th terms (extremes) = product of 2^nd and 3^rd terms (means)
$$\eqalign{ & \Rightarrow {\text{2}}{\text{.5}}x = {\text{40}} \cr & \Rightarrow x = \frac{{40}}{{2.5}} = 16 \cr} $$