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CSAT 2026 paper

UPSC CSE CSAT 2026 · Question 9 · Counting, permutations & probability

How many words can one form by shuffling the letters of the word QUEUE, if Q is always followed by…

CSAT 2026 · Q9

Counting, permutations & probability Easy Provisional key

How many words can one form by shuffling the letters of the word QUEUE, if Q is always followed by U? The words thus formed need not necessarily have any meaning.

Answer & explanation

Answer: (d) 12

Glue Q and U together as one block 'QU'. Then arrange four units — QU, U, E, E — where the two E's are identical: 4!/2! = 12.

  1. QUEUE has Q, U, U, E, E.
  2. Tie Q to a U as a block: the units are QU, U, E, E.
  3. Arrangements = 4! ÷ 2! (two identical E's) = 24 ÷ 2 = 12.
  4. Check: Q occurs once, so each word has exactly one block position — no word is counted twice.

Remember · 'X always followed by Y' → treat XY as one block, then divide by factorials of repeated letters.

Question and answer: UPSC's provisional GS Paper II (2026, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·

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