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: river stone flame eagle bread koala
Step I: bread river stone flame eagle koala
Step II: bread eagle river stone flame koala
Step III: bread eagle flame river stone koala
Step IV: bread eagle flame koala river stone
Step IV is the last step of this input.
Step II of another input is: acorn badge yacht lily melon dune
Following the same rule, which of the following will be Step IV for that input?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → acorn badge dune lily yacht melon
Compare each step of the illustration with the one before it. In each step, the word that comes first in dictionary order among the words not yet arranged moves to the next place from the left end, and all the other words keep their order.
Step I: ‘bread’ comes first in dictionary order, so it moves to the first place from the left
Step II: ‘eagle’ comes first in dictionary order, so it moves to the second place from the left
Step III: ‘flame’ comes first in dictionary order, so it moves to the third place from the left
Step IV: ‘koala’ comes first in dictionary order, so it moves to the fourth place from the left
After Step IV the words stand in dictionary order, so the arrangement is complete.
In Step II the first two elements, acorn badge, are already in place. Continue from Step II with the same rule.
Step III: ‘dune’ comes first in dictionary order, so it moves to the third place from the left, giving acorn badge dune yacht lily melon
Step IV: ‘lily’ comes first in dictionary order, so it moves to the fourth place from the left, giving acorn badge dune lily yacht melon
So Step IV is acorn badge dune lily yacht melon.
Why the other options are incorrect
Option (2) acorn badge dune yacht lily melon — Incorrect. This is Step III; in Step IV ‘lily’ must also move up.
Option (3) acorn badge dune lily melon yacht — Incorrect. This is Step V, where ‘melon’ has also been moved.
Option (4) acorn badge lily dune yacht melon — Incorrect. ‘dune’ comes before ‘lily’ in dictionary order, so ‘dune’ must be third.