Select the option that is related to the seventh number in file same way as the second number is related to the first number. the fourth number is Belated to file third number and file sixth number is related to tile fifth number.
20 : 5 :: 56 : 8 :: 12 : 4 :: 42 : ?

Given: 20 : 5 :: 56 : 8 :: 12 : 4 :: 42 : ?

Logic: (2nd Number)² − 2nd Number = 1st Number

(5)²- 5 = 25 - 5 = 20

(8)²- 8 = 64 - 8 = 56

(4) ²- 4 = 16 - 4 = 12

Take ? = 7 (from the Options)

(7)²- 7 = 42 (satisfied)

Thus, the correct option is (a) 7

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