Three of the following four number pairs are alike in a certain way and one is different. Find the odd one out.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 29 : 812
In three of the pairs, the second number is the first number times the next number, \(n:n(n+1)\).
Option (1) 17 : 306 — \(17\times18=306\), the rule holds.
Option (2) 29 : 812 — \(29\times30=870\), not 812; 812 is \(28\times29\), the first number times the number before it, so 29 : 812 is the odd one out.
Option (3) 16 : 272 — \(16\times17=272\), the rule holds.
Option (4) 22 : 506 — \(22\times23=506\), the rule holds.