Optiver 80 in 8

The classic Optiver mental math test: 80 questions, 8 minutes, four choices each.

• 80 questions, one at a time. No going back.
• 8:00 on the clock. It does not pause.
• +1 for a correct answer, −1 for a wrong one, 0 for a skip.
• Answer with keys 1–4, skip with S (or click).