Sequences & Probability — Free Practice Test
60 typed-answer questions in 10 minutes, +1 per correct answer, −1 per wrong answer, skips are free. Number-series pattern recognition and quick probability/expected-value calculation — the two skills that show up across almost every trading-firm assessment, in a generic format not tied to one specific firm. Free, no signup — one fixed practice set, the same questions in the same order every time.
60 questions · 10 minutes · typed answers
Number-series pattern recognition and quick probability/EV calculation, typed input. +1 correct, −1 wrong, skips are free. This format isn't tied to one specific firm's real cutoff — 40 net is a reasonable target to aim past.
This is one fixed set — the same 60 questions in the same order for everyone, every time, so scores here are directly comparable. For a brand new set every day, per-topic practice with explanations, and progress tracking, that's the TradeMind app.
What this test covers
Almost every trading-firm online assessment includes some version of these two question families alongside pure arithmetic: spot the pattern in a number series, and compute a probability or expected value fast enough that it feels automatic rather than derived from scratch. Neither skill has a single "correct" firm to attribute it to — Optiver, Jane Street, SIG, and dozens of others all test some version of both — so this simulator is built as a standalone practice format rather than a reconstruction of one company's exact test.
| Length | 60 questions · 10 minutes (10 seconds per question) |
|---|---|
| Input | Typed answers (open input, not multiple choice) |
| Scoring | +1 correct · −1 wrong · 0 skipped |
| Content | Number sequences · dice & card probability · expected value |
Reading a sequence fast
The fastest approach is mechanical, not clever: write out the differences between consecutive terms first. If those differences are constant, it's arithmetic — add that constant to the last term. If the differences of the differences are constant, it's a quadratic-feel series — extend the difference pattern one more step, then add it. If dividing consecutive terms gives a constant ratio, it's geometric. If a term equals the sum of the two before it, it's Fibonacci-style. Checking these four possibilities in order, mechanically, is faster and more reliable under time pressure than trying to "see" the pattern by staring at it.
Probability under time pressure
Most of these questions reduce to counting: how many outcomes match what's asked, divided by how many outcomes are possible in total. Two dice summing to a target has a fixed, memorisable table (7 is the most common sum, with 6 out of 36 combinations; 2 and 12 are the rarest, with 1 each). Expected value is just a weighted average — multiply each outcome by its probability and add. The speed comes from not re-deriving these from scratch every time, the same way multiplication tables save time over repeated addition.
FAQ
Is this based on one specific firm's test?
No — unlike this site's other simulators, Sequences & Probability isn't a reconstruction of any single firm's assessment. Number-series pattern recognition and quick probability/EV calculation show up across almost every trading-firm online test in some form, so this is a generic practice format for both skills rather than a copy of one company's exact question bank.
What kinds of sequences show up?
Arithmetic (constant difference), geometric (constant ratio), quadratic-feel series (constant second difference), Fibonacci-style (each term is the sum of the two before it), and alternating-step patterns (add, subtract, add, subtract). Every sequence gives five or six terms and asks for the next one.
What kinds of probability questions show up?
Two-dice sum probabilities, expected value of a die roll with a payout multiplier, coin-flip run probabilities, card-draw probabilities from a standard deck, expected value of a simple win/lose bet, and "at least one" / "none at all" probabilities over several die rolls.
How should I answer — decimal or fraction?
Either. Typing 5/36 or 0.1389 both grade as correct for a probability question, and whole numbers or clean decimals work for expected-value questions. There's no multiple choice here — every answer is typed.
Is there a real pass mark?
No official one — this format isn't attributed to a specific firm's real cutoff, so there's nothing to report accurately. 40 net (out of a possible 60, with −1 per wrong answer) is a reasonable target to aim comfortably past, not a claimed industry bar.
TradeMind is an independent training tool. This simulator is a generic practice format for number-series and probability/EV questions and is not a reconstruction of any specific firm's assessment, and is not affiliated with, endorsed by, or sponsored by any firm mentioned elsewhere on this site. Question content is procedurally generated and does not reproduce actual test material.