Four number-pairs have been given, out of which three are alike in some manner and one is different. Select the one that is different.
(NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. Eg 13-Operations on 13 such as adding/subtracting/multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)
11 : 92
17 : 146
31: 284
21 : 182
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 31: 284.
Logic: [(First no. × 9) - 7] = Second no.
Option (1) 21: 182 →
= [(21 × 9) - 7] = 189 - 7 =182
Option (2) 11: 92 →
= [(11 × 9) - 7] = 99 - 7 = 92
Option (3) 17: 146 →
= [(17 × 9) - 7] = 153 - 7 = 146
Option (4) 31: 284 →
= [(31 × 9) - 7 ] = (279 -7 ) = 272 ≠ second no.
Thus, 31: 284 is different from the rest options as it does not follow the logic.