Black Wednesday — Daily puzzle for 2026-09-27

Very Hard — logic-grid deduction puzzle

After a wild day for the pound in September 1992, Ursula works out who traded what, using her memory and a pad of notes with one false note among them.

It was a Wednesday in September 1992, and the pound was falling fast. On one trading floor the phones never stopped ringing, and the screens flashed from early morning till late at night. Three young dealers, Graham, Nadia and Trevor, each had a desk of their own, and each spent the whole day buying and selling one foreign currency against the pound. Jackets came off in the late summer heat, but every tie stayed on, and each dealer kept going on just one drink all day long. The next morning Ursula, who ran the floor, had to write down who had made how many deals. She had her own memory of the day and a pad of notes scribbled in the rush. She also knew that one of those notes was wrong.

Clues

  1. Note A: Graham drank water all day.
  2. Note B: when the three dealers were ranked by number of deals, Nadia and the dealer at the pillar desk came next to each other.
  3. Note C: if the dealer at the pillar desk made 18 deals, then the tea drinker did not sit at the window desk.
  4. Only one of the notes A, B and C was false.
  5. Whoever wore the plain tie traded lire.
  6. The lire trader and the marks trader made 27 deals between them.
  7. Graham, the dealer who made 9 deals and the dealer at the pillar desk were three different people.
  8. Just two of these three things were true: the tea drinker traded marks; the dealer at the window desk made 9 deals; Trevor sat at the door desk.
  9. The door desk did not belong to the dealer who made 9 deals.
  10. Trevor did not trade marks if the tea drinker sat at the window desk.
  11. Over the whole day, the coffee drinker and the tea drinker made 32 deals between them.
  12. If Trevor traded something other than marks, the dealer at the window desk did not wear the spotted tie.

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