In a certain code language, ‘CONFUSED’ is coded as ‘7’ and ‘CHAIN’ is coded as ‘4’. How will ‘ADULTHOOD’ be coded in that language?

Correct — C. Rule: count the letters in the word, then subtract 1.

CONFUSED has 8 letters → 8 − 1 = 7
CHAIN has 5 letters → 5 − 1 = 4

ADULTHOOD: A, D, U, L, T, H, O, O, D — that is 9 letters.
9 − 1 = 8, which is option (c).

Why the others are wrong

• (a)
  6 — 6 needs a 7-letter word. Seven is the count of ADULTHOOD's *distinct* letters, because O and D each appear twice — but the rule counts every letter, giving nine.
• (b)
  7 — 7 is the code the question gives for CONFUSED, an 8-letter word. ADULTHOOD is a letter longer, so it cannot share that code.
• (d)
  9 — 9 is the letter count itself, with the subtraction forgotten. Both worked examples subtract one: 8 letters give 7, and 5 letters give 4.

When a whole word codes to a single small number, the code is a count of something, not a sum of alphabet positions — a sum for CONFUSED would run to 87.

So test the cheap counts: total letters, vowels, consonants, distinct letters. CONFUSED (8 letters, code 7) and CHAIN (5 letters, code 4) both sit exactly one below the letter count.

Vowels and consonants do not fit: CONFUSED has 3 vowels and 5 consonants, CHAIN has 2 and 3. Letters minus one is the rule, and the rest is counting carefully.

Key facts

• CONFUSED has 8 letters and is coded 7, and CHAIN has 5 letters and is coded 4.
• ADULTHOOD has 9 letters, so its code is 9 − 1 = 8.
• ADULTHOOD contains only 7 distinct letters, because O and D each occur twice.

Common traps

• Counting the distinct letters of ADULTHOOD, getting 7, and answering 6
• Miscounting a nine-letter word that carries two repeated letters
• Adding alphabet positions when the given codes are far too small to be sums

No directly related past PYQ was found.