Mock round · Interleaved
Mixed mock: everything, shuffled, timed
Real interviews jump from VLOOKUP to trains to p-values without warning. Mixing topics is harder than practising them in blocks, and that difficulty is what makes the knowledge stick for interview day.
13 rapid-fire questions
Excel =XLOOKUP("E200", A2:A6, D2:D6). E200 doesn't exist, and there's no 4th argument. What do you get?
SQL SELECT dept, AVG(salary) FROM emp WHERE AVG(salary) > 50000 GROUP BY dept. What's wrong?
Stats What is the mean of 4, 8, 15, 16, 23, 42?
Puzzle 6 L and 4 L jugs. Can you get 2 L?
Aptitude A 200 m train crosses a 300 m bridge in 25 s. What's its speed in km/h?
Aptitude In an AP, the 3rd term is 12 and the 7th term is 28. What is d?
Aptitude 1, 8, 27, 64, ?
Aptitude If DOG = 26 (sum of positions), what is CAT?
Excel The manager wants each region's share of total sales in the pivot. What do you use?
Stats H₀: "this transaction is legitimate". What is a Type II error?
Stats What does a VIF of 1 mean?
SQL customers (100 rows) LEFT JOIN orders gives 250 rows. Why?
Excel VLOOKUP returns another employee's salary for an ID that doesn't exist. What's the most likely cause?
3 typed answers
Aptitude Sum of 1 + 2 + … + 20?
Excel Prices are in A2:A50, product names in B2:B50. Return the price of the product named in H2.
Aptitude Code DATA with the opposite-letter rule.
Say-it-aloud round (no peeking)
Answer each out loud in under 45 seconds, then open it to compare.
"How is a LEFT JOIN different from VLOOKUP?"
Both keep every row of the main table. VLOOKUP returns only the first match (or #N/A). A LEFT JOIN returns all matches, so rows can multiply, and gives NULL for no match. It can also return many columns and join on multiple keys."What's the order of execution of a SQL query?"
FROM/JOIN → WHERE → GROUP BY → HAVING → SELECT → ORDER BY → LIMIT. That's why aliases and aggregates can't be used in WHERE."Type I vs Type II error, with an example?"
Type I: rejecting a true H₀ (false positive, α), e.g. shipping a feature that does nothing. Type II: failing to reject a false H₀ (false negative, β), e.g. missing a feature that works. Power = 1 − β."What is multicollinearity and how do you handle it?"
Predictors highly correlated with each other. It makes coefficients unstable. Detect with a correlation matrix and VIF (> 5–10). Fix by dropping or combining variables, or with ridge regression."Mean or median for salaries?"
Median, because salaries are right-skewed and a few high earners pull the mean up.Your turn
- Attempt 1 (Day 6): note your score and the topics you missed.
- Re-do the "Your turn" list of each lesson linked from a wrong answer.
- Ask your teacher for a fresh mixed set focused on your weak topics.
- Attempt 2 (2 days later): reload the page and aim for 15/16.
- Interview morning: say-it-aloud round only, plus a skim of the cheat sheets.
Cheat sheets: Excel · SQL · Stats · Aptitude & GD