The second number in the given number-pairs is obtained by performing certain mathematical operation(s) on the first number. The same operation(s) is/are followed in all the number-pairs, except one. Find that odd number-pair.

(NOTE: The relation should be found without breaking down the numbers into its constituent digits)

Question

Question

This question was previously asked in

SSC CGL 2023 Tier-I Official Paper (Held On: 17 Jul 2023 Shift 3)

Answer 1

Logic : Square root of 1st number = Square root of 2nd number - 1

So,

\({ \sqrt{225} }\) = \({ \sqrt{169} }\) - 1

15 = 13 - 1

15 ≠ 12 (LHS ≠ RHS)

\({ \sqrt{361} }\) = \({ \sqrt{400} }\) - 1

19 = 20 - 1

19 = 19 (LHS = RHS)

\({ \sqrt{529} }\) = \({ \sqrt{576} }\) - 1

23 = 24 - 1

23 = 23 (LHS = RHS)

\({ \sqrt{441} }\) = \({ \sqrt{484} }\) - 1

21 = 22 - 1

21 = 21 (LHS = RHS)

Hence, "Option - (1)" is the correct answer.