▸case-01 In January, Acme SaaS started with 1,000 active subscribers. During January, 100 subscribers canceled, and 200 new subscribers joined, ending with 1,100 subscribers. Calculate the monthly churn rate for January. | pass→pass | 4,225 | 6,499 | +54% | 1 | 1 | 0% | 870 | 1,423 | +64% | 0 | 0 | — |
▸case-02 A customer feedback survey for MobileApp v2.4 received 200 total responses: 110 scored 9-10, 50 scored 7-8, and 40 scored 0-6. Compute the Net Promoter Score for this release. | pass→pass | 4,644 | 4,405 | -5% | 1 | 1 | 0% | 926 | 1,051 | +13% | 0 | 0 | — |
▸case-03 E-commerce platform StoreFront had 3 store categories yesterday: Fashion (10 orders, $500 total revenue, average $50), Electronics (2 orders, $1000 total revenue, average $500), and Books (8 orders, $160 total revenue, average $20). Calculate the overall Average Order Value across all categories. | pass→pass | 4,748 | 4,577 | -4% | 1 | 1 | 0% | 970 | 1,044 | +8% | 0 | 0 | — |
▸case-04 In Q3, LogiTech spent $50,000 on Google Ads marketing and $30,000 on sales team salaries. During Q3, they gained 400 total new users, of which 100 were paying customers and 300 were free-tier users. Calculate the paid Customer Acquisition Cost (CAC). | pass→pass | 5,490 | 6,259 | +14% | 1 | 1 | 0% | 981 | 1,351 | +38% | 0 | 0 | — |
▸case-05 A software audit of module AuthCore analyzed 25,000 lines of code (25 KLOC) and recorded 15 critical bugs, 25 major bugs, and 10 minor bugs during testing. Compute the overall Defect Density per 1,000 lines of code (KLOC). | pass→pass | 3,956 | 4,747 | +20% | 1 | 1 | 0% | 704 | 1,120 | +59% | 0 | 0 | — |
▸case-06 An online ad campaign for CloudSync generated 50,000 impressions, 2,000 ad clicks, and 100 product purchases. Calculate both the Click-Through Rate (CTR) and the Conversion Rate (CR) with explicit formulas and denominators. | pass→pass | 5,337 | 7,127 | +34% | 1 | 1 | 0% | 1,169 | 1,577 | +35% | 0 | 0 | — |
▸case-07 StreamFlix had $120,000 in monthly recurring revenue in August and $150,000 in September. Calculate the Month-over-Month (MoM) revenue growth rate and absolute delta. | pass→pass | 3,804 | 4,407 | +16% | 1 | 1 | 0% | 784 | 1,052 | +34% | 0 | 0 | — |
▸case-08 On news portal MediaDaily, page /article-123 had 1,000 total pageviews across 800 sessions. In 200 of those sessions, /article-123 was the first page visited, and in 50 of those 200 entrance sessions, the visitor left without visiting any other page. Calculate the Bounce Rate for /article-123. | pass→pass | 4,775 | 6,287 | +32% | 1 | 1 | 0% | 888 | 1,264 | +42% | 0 | 0 | — |
▸case-21 We are training an XGBoost fraud classifier on credit card transactions with a 0.01% positive fraud rate. How should we set up our cross-validation and evaluation strategy to avoid data leakage and optimistic bias across time? | fail→fail | 18,979 | 14,639 | -23% | 1 | 1 | 0% | 3,085 | 2,656 | -14% | 0 | 0 | — |
▸case-09 Enterprise SaaS startup DataPipeline generated $45,000 in subscription revenue during the month of November. Calculate the Annual Run Rate (ARR) based on this monthly performance, and state any aggregation assumptions. | fail→fail | 5,696 | 3,669 | -36% | 1 | 1 | 0% | 1,062 | 744 | -30% | 0 | 0 | — |
▸case-10 WidgetCorp reported total revenue of $500,000, Cost of Goods Sold (COGS) of $200,000, and Operating Expenses (OpEx) of $150,000 in Q2. Compute the Gross Margin percentage. | pass→pass | 3,742 | 4,165 | +11% | 1 | 1 | 0% | 723 | 927 | +28% | 0 | 0 | — |
▸case-11 SupplyChain Inc had a Cost of Goods Sold (COGS) of $1,200,000 for the fiscal year. At the start of the year, inventory was valued at $200,000, and at the end of the year, inventory was $400,000. Total revenue was $2,000,000. Calculate the Inventory Turnover Ratio. | pass→pass | 4,004 | 5,223 | +30% | 1 | 1 | 0% | 805 | 1,189 | +48% | 0 | 0 | — |
▸case-12 For active users on FitnessPlus, average monthly revenue per user (ARPU) is $20. The average monthly churn rate is 5%. Assuming 0% discount rate and direct churn-based lifespan estimation, calculate the simplified Customer Lifetime Value (LTV). | pass→pass | 3,894 | 3,099 | -20% | 1 | 1 | 0% | 806 | 842 | +4% | 0 | 0 | — |
▸case-22 We increased prices in Region A by 10% in June while keeping Region B unchanged as a control group. Here are the monthly sales numbers for both regions before and after June. Estimate the causal impact of the price change using a Difference-in-Differences statistical regression model. | pass→pass | 11,629 | 8,926 | -23% | 1 | 1 | 0% | 2,316 | 1,892 | -18% | 0 | 0 | — |
▸case-13 Social network AppPulse recorded 150,000 Daily Active Users (DAU) on average during October, and a total of 600,000 Monthly Active Users (MAU) in October. Calculate the DAU/MAU stickiness ratio and convert it to a percentage. | pass→pass | 3,894 | 4,673 | +20% | 1 | 1 | 0% | 813 | 998 | +23% | 0 | 0 | — |
▸case-14 Server Cluster Ops monitored 10 identical servers over a 1,000-hour operational period (10,000 total machine-hours). During this period, a total of 8 failure incidents occurred, each taking 5 hours to repair (40 total repair hours). Calculate the Mean Time Between Failures (MTBF). | pass→fail | 7,715 | 7,239 | -6% | 1 | 1 | 0% | 1,538 | 1,630 | +6% | 0 | 0 | — |
▸case-15 At the start of the year, a cohort of enterprise clients generated $100,000 in MRR. Over the year, existing clients in this cohort expanded by $20,000 MRR, downgraded by $5,000 MRR, and churned completely by $10,000 MRR. Calculate the Net Retention Rate (NRR) percentage for this cohort. | pass→pass | 4,439 | 4,623 | +4% | 1 | 1 | 0% | 898 | 1,064 | +18% | 0 | 0 | — |
▸case-16 Quality Assurance checked 3 code repositories for test coverage: Repo A (100 lines, 90% coverage), Repo B (200 lines, 80% coverage), and Repo C (700 lines, 50% coverage). Verify the overall codebase test coverage percentage using correct aggregation scope. | pass→pass | 5,411 | 5,703 | +5% | 1 | 1 | 0% | 1,132 | 1,252 | +11% | 0 | 0 | — |
▸case-17 E-commerce seller ShoeStore spent $10,000 on ad campaigns. The campaign generated $40,000 in gross revenue. The Cost of Goods Sold (COGS) for products sold via these ads was $15,000. Calculate Return on Ad Spend (ROAS) ratio and express it clearly. | pass→pass | 6,381 | 6,162 | -3% | 1 | 1 | 0% | 1,240 | 1,461 | +18% | 0 | 0 | — |
▸case-18 Support Desk DeskHero handled 500 total customer tickets in March. 350 tickets were resolved on the first interaction. 100 tickets required 2 interactions. 50 tickets were closed as duplicate or invalid entries without customer contact. Calculate the First Contact Resolution (FCR) rate. | pass→pass | 6,284 | 6,328 | +1% | 1 | 1 | 0% | 1,320 | 1,430 | +8% | 0 | 0 | — |
▸case-19 Tech startup CloudBase has $600,000 in cash reserves. In November, total cash inflow was $50,000 and total cash outflow was $150,000. Compute the net monthly burn rate and remaining runway in months assuming constant burn. | pass→pass | 4,249 | 5,103 | +20% | 1 | 1 | 0% | 826 | 1,148 | +39% | 0 | 0 | — |
▸case-20 SaaS company MetricCloud started Q1 with 100 enterprise customers generating $200,000 in MRR. During Q1, 5 customers churned completely, representing $30,000 of lost MRR. No other changes occurred. Calculate both Customer Churn Rate and Gross Revenue Churn Rate. | pass→pass | 5,965 | 5,158 | -14% | 1 | 1 | 0% | 1,162 | 1,329 | +14% | 0 | 0 | — |
▸case-23 We have finalized quarterly revenue numbers ($1.2M, $1.5M, $1.1M, $1.8M). How should we design the chart layout, visual hierarchy, and color palette to present this quarterly trend effectively to executives? | pass→pass | 16,487 | 10,141 | -38% | 1 | 1 | 0% | 2,827 | 1,886 | -33% | 0 | 0 | — |