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Hard · Probability & Statistics · Quant Trader interview question · probability, expected-value, inclusion-exclusion, coupon-collector
A cereal company is running a promotion where each box contains one of three different coupons. The probabilities of finding coupon A, B, and C are 1/2, 1/3, and 1/6 respectively. Assume that coupons are distributed independently. What is the expected number of boxes you need to buy to collect at least one of each coupon type?