Uplift

numeric

Expected cost of a rider coupon

Digital & Marketing Analytics · Campaign & Funnel Analytics · easy · Reported at Lyft · 8 min

Lyft gives a $5 coupon to 20,000 riders. Each rider independently has a 35% probability of using it, and redemption is limited to one coupon per rider. What is the expected total coupon cost? Answer as a dollar amount without symbols or commas, for example 12500.

Evaluation criteria

  • Does not require independence for the expectation calculation
  • Uses the correct method or distribution
  • Shows the calculation
  • Rounds as the prompt asks

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Source

Adapted from a reported Lyft interview question on StrataScratch(opens in a new tab).

Your answer

USD

Commas, currency symbols and a trailing percent sign are fine. Answers within ±50 USD of the expected value are accepted.

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