A word arrangement machine, when given an input line of words, rearranges them step by step following a particular rule. An illustration of an input and its rearrangement is given below.
Input: pen hut mug cot jar fig bat lid
Step I: lid hut mug cot jar fig bat pen
Step II: lid bat mug cot jar fig hut pen
Step III: lid bat fig cot jar mug hut pen
Step IV: lid bat fig jar cot mug hut pen
Step IV is the last step of this input.
Step II of another input is: sun cap leaf map rose drum mat tea
Following the same rule, what was that input?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → tea mat leaf map rose drum cap sun
Compare each step of the illustration with the one before it. The machine works by places, not by the words: Step I interchanges the 1st and the last word, Step II the 2nd word from each end, Step III the 3rd word from each end, and so on.
Step I: the words in the first place from the left (pen) and the first place from the right (lid) change places
Step II: the words in the second place from the left (hut) and the second place from the right (bat) change places
Step III: the words in the third place from the left (mug) and the third place from the right (fig) change places
Step IV: the words in the fourth place from the left (cot) and the fourth place from the right (jar) change places
After Step IV every pair of places from the two ends has been interchanged, so the arrangement is complete.
Each step only interchanges two places, and interchanging the same two places again puts the words back. So undo the steps one by one, starting from Step II.
Undo Step II: interchange the second words from each end again (cap and mat), giving sun mat leaf map rose drum cap tea
Undo Step I: interchange the first words from each end again (sun and tea), giving tea mat leaf map rose drum cap sun
Check: for the input tea mat leaf map rose drum cap sun, Step I is sun mat leaf map rose drum cap tea and Step II is sun cap leaf map rose drum mat tea, which is the given line. So the input was tea mat leaf map rose drum cap sun.
Why the other options are incorrect
Option (1) tea cap leaf map rose drum mat sun — Incorrect. For this input Step II is sun mat leaf map rose drum cap tea, not the given line; only Step I has been undone.
Option (3) sun mat leaf map rose drum cap tea — Incorrect. This is Step I of the input; for it Step II would be tea cap leaf map rose drum mat sun.
Option (4) tea mat drum map rose leaf cap sun — Incorrect. Here the third words from each end have also been interchanged; for this input Step II is sun cap drum map rose leaf mat tea.