Question : Directions: Select the option related to the sixth number in the same way as the first number is related to the second number and the third number is related to the fourth number.
13 : 168 :: 16 : 255 :: ? : 143
Option 1: 14
Option 2: 15
Option 3: 11
Option 4: 12
Correct Answer: 12
Solution :
Given:
13 : 168 :: 16 : 255 :: ? : 143
Subtract 1 from the square of the first number, to get the second number in each number pair –
Like, 13 : 168→13
2
– 1 = 169 – 1 = 168
And, 16 : 255→16
2
– 1 = 256 – 1 = 255
Similarly, follow the same pattern for ? : 143→
⇒ x
2
– 1 = 143
⇒ x
2
= 143 + 1
⇒ x = √144
⇒ x = 12
So, 12 is related to 143. Hence, the fourth option is correct.