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Capital One·Data Scientist·Technical Phone Screen·Intermediate

Intermediate
May 2026

Summary

Capital One data scientist interview with a pretty involved restaurant economics case. The whole thing was basically one long quantitative problem broken into parts, and they wanted you to show your work and label everything precisely.

Questions Asked (4)

Q1

Given a restaurant with 20 tables per day, $30 average revenue per table, variable costs at 40% of revenue, and $100 fixed costs daily, what is the baseline daily profit?

Product Analytics & MetricsPricing & Monetization
Author's notes

Straightforward setup question but I second-guessed myself on whether VC applied to gross revenue or net.

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AI HintsAI Generated

Suggested Approach

Start by clearly stating the formula for daily profit: Profit = Revenue - Variable Costs - Fixed Costs. Then compute each component step-by-step, showing your calculations and assumptions, and finally arrive at the baseline daily profit.

Pro tip: After calculating the baseline, briefly mention that this is a simplified model and that in a real business context, you would consider factors like seasonality, customer acquisition costs, and capacity constraints. This shows you think beyond the immediate numbers.

1. Identify given values

List the provided numbers: 20 tables per day, $30 average revenue per table, variable costs at 40% of revenue, and $100 fixed costs daily.

2. Calculate total daily revenue

Multiply the number of tables by the average revenue per table: 20 * $30 = $600.

3. Calculate variable costs

Compute 40% of total revenue: 0.40 * $600 = $240.

4. Compute daily profit

Subtract variable costs and fixed costs from revenue: $600 - $240 - $100 = $260.

5. State the result and assumptions

Clearly state the baseline daily profit is $260, and note any assumptions such as constant demand and no other costs.

Key Points to Mention

  • Revenue calculation: tables * average revenue per table
  • Variable costs as a percentage of revenue
  • Fixed costs are independent of revenue
  • Profit formula: Revenue - Variable Costs - Fixed Costs
  • Assumption of linearity and no other costs
  • Baseline profit is before taxes, interest, and other expenses

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.

Q2

If all 20 tables used a coupon and the coupon platform takes a 40% commission on each table's check, what average check per table would keep daily profit equal to the baseline?

Pricing & MonetizationProduct Analytics & Metrics
Author's notes

This is where I got a little tangled.

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AI HintsAI Generated

Suggested Approach

First, clarify the baseline daily profit and the average check per table under normal conditions. Then, model the new profit equation with the 40% commission and solve for the average check that equates the new profit to the baseline. Present the calculation clearly and discuss any assumptions.

Pro tip: Always state your assumptions explicitly (e.g., baseline average check, number of tables, daily profit) and show the algebra step-by-step. This demonstrates rigor and helps the interviewer follow your logic.

1. Define baseline profit

Let baseline daily profit be P, average check per table be A, and number of tables be 20. So P = 20 * A (assuming no other costs).

2. Model new profit with commission

With 40% commission, the platform takes 0.4 * check, so the restaurant keeps 0.6 * check per table. New profit = 20 * 0.6 * X, where X is the new average check.

3. Set equal to baseline and solve

Set 20 * 0.6 * X = 20 * A, which simplifies to 0.6X = A, so X = A / 0.6 = 1.6667 * A. Thus, the new average check must be about 66.7% higher than the baseline.

4. Interpret and discuss implications

Explain that to maintain profit, the average check must increase by 66.7% when all tables use a coupon with 40% commission. Discuss feasibility and potential strategies.

Key Points to Mention

  • Baseline profit calculation: profit = number of tables * average check (assuming no variable costs).
  • Commission reduces revenue per table to 60% of the check.
  • Equation: 20 * 0.6 * X = 20 * A, leading to X = A / 0.6.
  • Percentage increase: (X - A)/A = 1/0.6 - 1 = 66.7%.
  • Assumption: no change in costs or number of tables; all tables use coupon.
  • Business implication: such a large increase may be unrealistic, so consider other factors like increased volume or cost savings.

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.

Q3

After joining the coupon platform, you now see 25 tables per day, 10 of which used a coupon. The overall average check across all 25 tables is $36. Variable and fixed costs are unchanged. Calculate the new daily profit and decompose the change versus baseline into three parts: the effect of more tables, the effect of a higher average check, and the cost of commissions on coupon tables.

Product Analytics & MetricsPricing & MonetizationRoot Cause Analysis
Author's notes

This was the meaty one.

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AI HintsAI Generated

Suggested Approach

First, clarify the baseline scenario and the assumptions about costs and commissions. Then compute the new daily profit by summing revenue from all tables and subtracting variable costs, fixed costs, and coupon commissions. Finally, decompose the profit change into volume, price (average check), and commission effects using a structured variance analysis.

Pro tip: When decomposing the profit change, use a sequential (step-by-step) approach to isolate each effect, and clearly state the order of decomposition to avoid double-counting. Also, explicitly state any assumptions about the commission rate and whether the average check increase applies to all tables or only coupon tables.

1. Clarify Baseline and Assumptions

Establish the baseline daily profit, the original number of tables, and the original average check. Confirm the commission rate per coupon table and whether fixed and variable costs per table remain constant.

2. Calculate New Daily Profit

Compute total revenue as 25 tables * $36 average check. Subtract variable costs (25 * variable cost per table), fixed costs, and commission costs (10 * commission per coupon table) to get the new daily profit.

3. Decompose Profit Change: Volume Effect

Calculate the profit impact of serving 25 tables instead of the baseline number, holding average check and commission structure constant. This isolates the effect of more tables.

4. Decompose Profit Change: Price Effect

Calculate the profit impact of the higher average check ($36 vs. baseline), holding the number of tables and commission structure constant. This isolates the effect of a higher average check.

5. Decompose Profit Change: Commission Effect

Calculate the profit impact of commissions paid on the 10 coupon tables, holding all else constant. This isolates the cost of commissions.

Key Points to Mention

  • Define baseline scenario: number of tables, average check, variable cost per table, fixed costs, and commission rate.
  • Assume variable costs scale with number of tables; fixed costs remain unchanged.
  • Commission is a variable cost per coupon table, reducing profit.
  • Use a sequential decomposition to avoid double-counting: first volume, then price, then commission.
  • Clearly state that the average check increase may apply to all tables or only coupon tables; if only coupon tables, adjust calculation accordingly.
  • Present the decomposition as a bridge from baseline profit to new profit, summing to the total change.

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.

Q4

Based on the numbers from the previous scenario, is profit up or down versus baseline, by how much, and what is the main driver of that change?

Product Analytics & MetricsPricing & Monetization
Author's notes

Profit is down $64.

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AI HintsAI Generated

Suggested Approach

First, restate the baseline and current profit figures from the previous scenario to confirm understanding. Then calculate the absolute and percentage change, and decompose the profit change into its key drivers (e.g., revenue, cost, volume, price) to identify the main contributor. Finally, clearly state whether profit is up or down, by how much, and name the primary driver.

Pro tip: Always quantify the impact of each driver and compare their relative contributions; this shows you can prioritize factors and communicate insights effectively to stakeholders.

1. Clarify baseline and current values

Restate the baseline profit and the current profit from the previous scenario to ensure alignment and avoid misinterpretation.

2. Calculate change

Compute the absolute difference and percentage change in profit to determine if it is up or down and by how much.

3. Decompose profit drivers

Break down profit into components such as revenue (price × volume) and costs (fixed and variable) to analyze which factor changed most significantly.

4. Identify main driver

Compare the magnitude of each driver's contribution to the total profit change and determine which one had the largest impact.

5. Summarize and communicate

Concisely state the direction and size of the profit change, and clearly name the main driver, supporting with numbers.

Key Points to Mention

  • Absolute and percentage change in profit
  • Direction of change (up or down)
  • Decomposition of profit into revenue and cost components
  • Impact of volume vs. price changes
  • Quantification of each driver's contribution
  • Clear identification of the primary driver

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.