The second number in the given number pairs is obtained by performing certain mathematical operation(s) on the first number. The same operation(s) are followed in all the number pairs except one. Find that odd number pair.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 64 : 9.
The logic used here is:
⇒2nd Number = (√1st number × 2) + 1
Option 1 →81 : 19
√81 x 2 + 1 = 9 x 2 + 1 = 18 + 1 = 19
Option 2 →121 : 23
√121 x 2 + 1 = 11 x 2 + 1 = 22 + 1 = 23
Option 3 →1 : 3
√1 x 2 + 1 = 1x 2 + 1 = 2 + 1 = 3
Except For Option 4 all the options follows the same pattern.
Hence, 64 : 9 is the correct answer.