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

27 : 841 :: 18 : 400 :: ? : 324

16

27 : 841 :: 18 : 400 :: ? : 324

The logic followed here is :

(Ist number+2)² = IInd number

As

(27+  2)²

= 29²

= 841

And

18 : 400

(18 +  2)²

= 20²

= 400

Similarly

? : 324

(A +  2)² = 324

(A +  2)² = 18²

(A +  2) = 18

A = 18 - 2

A = 16