In a certain code language, ‘What you think you become’ is written as ‘Fe Mo Su Ta Za’ and ‘What you think you achieve’ is written as ‘Mo Su Te Fe Za’. How will ‘achieve’ be written in that language?

Correct — D.

Rule: subtract the two sentences. What the English shares must be what the codes share; what differs must be what is left over.

Sentence 1: What you think you become = Fe Mo Su Ta Za
Sentence 2: What you think you achieve = Mo Su Te Fe Za

The words What you think you are common to both lines, and the codes common to both lines are Fe, Mo, Su and Za. Those four are therefore spoken for.

Sentence 1 alone carries Ta, and its one extra word is become, so Ta stands for become.
Sentence 2 alone carries Te, and its one extra word is achieve.

achieve = Te → option (d).

Why the others are wrong

• (a)
  Mo — Mo is printed in both lines. A code that survives when the last English word changes must belong to one of the words that did not change, so it cannot stand for achieve.
• (b)
  Fe — Fe is in both lines too. It belongs to the shared block What you think you, which is exactly why it appears whether the sentence ends in become or in achieve.
• (c)
  Za — Za is the third code common to both lines, fixed like Fe and Mo by the shared words. The code for achieve has to be one that appears in the second line and not in the first.

Substitution codes replace whole words, and the code tokens are deliberately shuffled, so position carries no information at all.

The method is subtraction. Line up the two sentences, strike out the English words they share and the code tokens they share, and whatever is left on each side must correspond.

You never need to decide which of the shared codes means what. The question only asks about a word that occurs in one sentence, and that word is answered by the leftover on the same side.

Key facts

• The codes are not printed in the order of the English words: Fe is first in one line and fourth in the other.
• Fe, Mo, Su and Za appear in both lines, Ta only in the first and Te only in the second.
• The sentences differ in exactly one English word, become against achieve, so exactly one code can differ.

Common traps

• Matching code to word by position instead of by which line each appears in.
• Picking a code that appears in both lines for a word that appears in only one.
• Answering Ta, which is the code for become rather than for achieve.

No directly related past PYQ was found.