Oct 08, 2026 by Offer

Optiver Interview Questions 2027: Full List & How to Answer

For Optiver interview questions like 'divide 2 by 17 to four decimal places,' work the long division aloud step by step — 2/17 = 0.1176 — then sanity-check by multiplying back. Never go silent; narrate every step. Commonly reported by candidates.

What This Question Assesses

Optiver hires for raw numerical fluency under pressure. This question tests whether you can do precise arithmetic mentally, stay calm, and verbalise your method — because on a trading floor, fast approximate-then-refine calculation is a survival skill. The interviewer is watching your process: do you freeze, do you guess, or do you work it out systematically and narrate as you go?

Optiver Interview Questions: How to Answer

Step 1 — Set up the long division aloud. "2 divided by 17. 17 goes into 20 once — 1, remainder 3. Bring down a zero: 30 — 17 goes in once — 1, remainder 13. Bring down a zero: 130 — 17 goes in 7 times (119), remainder 11. Bring down a zero: 110 — 17 goes in 6 times (102), remainder 8."
Step 2 — Read off the digits. "So 2/17 = 0.1176... to four decimal places, 0.1176."
Step 3 — Sanity-check. "Check: 0.1176 × 17 ≈ 2.0 — 0.1176 × 10 = 1.176, × 7 = 0.8232, total ≈ 1.999 — correct."
Step 4 — Narrate throughout. The golden rule of Optiver mental math: never go silent. Thinking aloud lets the interviewer follow your logic and give partial credit even if a digit slips.

An example line to say while working: "Seventeen into twenty goes once, remainder three; into thirty goes once, remainder thirteen; into one-thirty goes seven times, that's one-nineteen, remainder eleven; into one-ten goes six times — so 0.1176, and checking 0.1176 times 17 gives back 2."

Optiver Interview Questions: Common Mistakes

Going silent while calculating. Silence reads as freezing. Narrate every step — interviewers explicitly assess your working method, not just the answer.
No sanity check. A quick multiply-back catches arithmetic slips and shows trading-floor habits: always verify before acting on a number.
Giving up on a slip. One wrong digit is recoverable if your method is sound — correct yourself aloud and continue. Abandoning the problem is the real failure.

Mental math at Optiver is a trainable skill — daily timed practice on division, multiplication, and fractions is the highest-return preparation you can do.

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FAQ

What is the 80-in-8 test? Eighty mental arithmetic questions in eight minutes — a famous Optiver screening stage. It tests speed and accuracy under time pressure; practise with timed arithmetic drills.

How accurate do I need to be? Exact on straightforward questions like this one; fast and approximately right on estimation questions. Always show your method so partial credit is possible.

What if I make an arithmetic error mid-answer? Correct yourself aloud and keep going — "actually that remainder is 11, not 12, so..." Interviewers expect occasional slips; they penalise freezing, not correcting.

How should I practise? Daily timed sets: long division, two-digit multiplication, fraction-decimal conversions. Narrate your working aloud from the start so it becomes automatic.

Preparing for Optiver's interview? Our 2027 Optiver Online Assessment Exact Questions & Answers has practice questions and answers — $79 one-time, instant download.