Guess first — it makes the real numbers stick. Then see the typical range for people who complete a track like ours. (These are honest planning ranges, not a promise; your result depends on your effort and market.)
Being right matters. Knowing how sure to be matters just as much — in interviews, in debugging, in decisions. Answer true/false, and say how confident you are. We'll score not just your accuracy but your calibration: whether your 70% really means 70%.
Interviewers love "roughly how many…?" questions — not for the exact number, but to see you reason under uncertainty. Try each, then reveal the working. The skill is decomposing the problem, not memorising answers.
1. How many web requests might a busy e-commerce site handle per second at peak?
2. Roughly how many characters are in a typical 300-page book?
3. How much would 10,000 users each storing 5 MB of data need in total?
4. How many seconds are there in a working year (approx)?
Write down a decision and what you expect to happen. Reviewing these later trains your judgement — and shows how far you've come. Saved privately on this device only.
