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Capital One·Data Scientist·Technical Phone Screen·Intermediate

Intermediate
May 2026

Summary

Capital One Data Scientist case interview, heavy on unit economics and sensitivity analysis for a restaurant/Groupon scenario. Four parts, all math, no fluff. The kind of thing where you really need to slow down and not rush the algebra.

Questions Asked (4)

Q1

A restaurant has 20 tables per day with an average spend of $30 per table, variable costs at 40% of revenue, and fixed costs of $100 per day. What is the daily profit?

Product Analytics & MetricsPricing & Monetization
Author's notes

Straightforward setup: revenue is 20 times 30 which is 600, variable costs are 0.4 times 600 which is 240, subtract fixed costs of 100, so profit is 260.

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AI HintsAI Generated

Suggested Approach

Break the problem into revenue, variable costs, and fixed costs, then compute profit step by step. State your assumptions clearly and show the arithmetic to demonstrate structured thinking.

Pro tip: After calculating, briefly mention how you'd sanity-check the result (e.g., profit margin) and note any assumptions that could affect the answer—this shows business acumen beyond raw math.

1. Calculate total revenue

Multiply the number of tables by the average spend per table to get daily revenue.

2. Compute variable costs

Apply the 40% variable cost rate to the revenue to find total variable costs.

3. Subtract variable costs from revenue

This gives the contribution margin, which covers fixed costs and profit.

4. Subtract fixed costs

Deduct the daily fixed costs from the contribution margin to arrive at daily profit.

5. State the final profit and sanity-check

Present the final dollar amount and optionally compute profit margin to verify reasonableness.

Key Points to Mention

  • Revenue = 20 tables × $30/table = $600
  • Variable costs = 40% × $600 = $240
  • Contribution margin = $600 - $240 = $360
  • Fixed costs = $100
  • Daily profit = $360 - $100 = $260
  • Profit margin = $260 / $600 ≈ 43.3% (sanity check)

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

Q2

Using a Groupon voucher model where customers pay $15 for a $30 voucher and Groupon keeps 40% of that $15, what is the break-even pre-discount spend per table for a voucher customer to contribute zero profit?

Pricing & MonetizationProduct Analytics & Metrics
Author's notes

This is where I got tripped up.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the cash flows: customer pays $15, Groupon keeps 40% ($6), so the business receives $9. The voucher gives the customer $30 of value, so the business must provide $30 in pre-discount goods/services. To break even (zero profit), the business's cost of goods sold (COGS) must equal the $9 received, meaning the pre-discount spend per table must be such that the COGS on that spend equals $9. Assuming a constant COGS percentage, solve for the pre-discount spend where COGS% × spend = $9. Alternatively, if the question implies the customer spends exactly the voucher amount ($30), then the break-even COGS% is 30%. But the question asks for break-even pre-discount spend per table, so we need to express spend in terms of COGS% or assume a typical COGS% and solve.

Pro tip: Always state your assumptions explicitly—especially the COGS percentage—and show how the answer changes with different COGS ratios. This demonstrates analytical rigor and business sense, which Capital One values.

1. Clarify the transaction

Identify the cash flows: customer pays $15, Groupon takes 40% ($6), business nets $9. The voucher entitles the customer to $30 of pre-discount value.

2. Define break-even condition

Break-even means profit = 0, so revenue to business ($9) must equal the cost of goods sold (COGS) for the redeemed voucher. Thus, COGS = $9.

3. Relate COGS to pre-discount spend

Let S be the pre-discount spend per table (the amount before the voucher discount). If the customer spends exactly $30, then S = $30. But if they spend more, S > $30. COGS = c × S, where c is the COGS percentage.

4. Solve for S

Set c × S = $9, so S = $9 / c. For example, if c = 30%, S = $30; if c = 40%, S = $22.50; if c = 20%, S = $45. The break-even pre-discount spend depends on the COGS ratio.

5. Interpret and discuss

Explain that if the actual pre-discount spend per table exceeds this break-even S, the voucher customer generates positive profit; if below, a loss. Also note that if the customer spends exactly the voucher amount ($30), the break-even COGS% is 30%.

Key Points to Mention

  • Groupon's 40% commission reduces the business's net revenue to $9 from the $15 voucher price.
  • The voucher's face value ($30) represents pre-discount spend, but actual spend may differ.
  • Break-even condition: COGS equals net revenue ($9).
  • The break-even pre-discount spend S = $9 / COGS percentage.
  • If the customer spends exactly $30, the break-even COGS percentage is 30%.
  • Sensitivity analysis: show how S changes with different COGS assumptions (e.g., 20%, 30%, 40%).

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

Q3

On a day with 25 tables total (10 using vouchers, 15 regular), where average pre-discount spend across all tables is $36, calculate the total daily profit using the given formulas for regular and coupon tables.

Pricing & MonetizationProduct Analytics & Metrics
Author's notes

Regular table profit is 0.6 times 36 which is 21.60.

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AI HintsAI Generated

Suggested Approach

First, clarify the given formulas for regular and coupon tables, as they are not provided in the question. Then, compute total revenue and total costs by applying the formulas to the respective table counts, using the average pre-discount spend of $36 to derive per-table values. Finally, sum the profits from regular and coupon tables to get the total daily profit.

Pro tip: In a real interview, always state your assumptions explicitly and ask for missing information—here, the formulas are critical. This demonstrates thoroughness and prevents you from solving the wrong problem.

1. Clarify the formulas and assumptions

Ask the interviewer to provide the exact formulas for profit per regular table and per coupon table, or state assumed formulas if not given. Confirm that the average pre-discount spend of $36 applies uniformly across all tables.

2. Compute per-table profit for each type

Using the formulas, calculate the profit for one regular table and one coupon table. For example, if regular profit = spend × margin and coupon profit = (spend - discount) × margin - redemption cost, plug in $36 and any given parameters.

3. Multiply by table counts

Multiply the per-table profit for regular tables by 15 and for coupon tables by 10 to get total profit from each segment.

4. Sum and sanity-check

Add the two totals to get daily profit. Perform a quick sanity check: ensure coupon table profit is lower than regular (due to discount) and that the overall profit is reasonable relative to total pre-discount revenue (25 × $36 = $900).

Key Points to Mention

  • Importance of clarifying missing formulas before calculating
  • Distinction between pre-discount spend and actual revenue after discounts
  • Impact of voucher redemption on profit margins
  • Weighted average approach if formulas involve variable costs
  • Sanity checking results against total revenue
  • Communicating assumptions clearly in a business context

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

Q4

Holding regular tables at $36 average spend and table counts fixed, what minimum average pre-discount spend per coupon table brings total daily profit back up to the baseline profit from part one?

Pricing & MonetizationProduct Analytics & MetricsProduct Strategy
Author's notes

You need daily profit to equal 260 again.

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AI HintsAI Generated

Suggested Approach

First, recall the baseline daily profit from part one and the current profit from regular tables and coupon tables at the current average spend. Then set up an equation where the total profit equals the baseline, solve for the required average pre-discount spend per coupon table, and verify that the solution is feasible given discount constraints.

Pro tip: Clearly state your assumptions about the discount structure and whether the coupon table spend is pre- or post-discount; this shows you understand the business context and avoid ambiguity.

1. Identify baseline profit and current components

From part one, note the baseline total daily profit. Also, identify the profit contribution from regular tables (fixed) and the current profit from coupon tables at the current average spend.

2. Set up the profit equation

Let x be the minimum average pre-discount spend per coupon table. Express total profit as regular table profit plus coupon table profit (which depends on x and the discount) and set it equal to the baseline profit.

3. Solve for x

Solve the equation for x, ensuring you account for any discount applied to coupon tables. If the discount is a percentage, the post-discount spend is x*(1 - discount rate).

4. Check feasibility and interpret

Verify that the calculated x is realistic (e.g., not exceeding maximum possible spend) and interpret the result in the context of the business problem.

Key Points to Mention

  • Baseline profit from part one
  • Fixed table counts and regular table average spend
  • Discount structure for coupon tables (e.g., percentage off)
  • Equation setup: total profit = baseline profit
  • Solving for pre-discount spend per coupon table
  • Feasibility check and business implications

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