Suppose that an urn contains two different types of coupons: three coupons of type A and...

 

Transcribed Image Text:

Suppose that an urn contains two different types of coupons: three coupons of type A and four coupons of type B. After Alice draws a coupon out of the urn, the urn is reset to its original state of having seven coupons: three coupons of type A and four coupons of type B (using an unlimited supply of spare coupons). Compute the expected number of draws needed for Alice to collect at least two coupons of each type (at least two of type A and at least two of type B). Do not round your answer to the nearest integer. Hint: If you need to cite basic properties (such as expectation-formula(e)) for certain probability distribution(s) as part of your work, you may do so without proof. Any random variables used should first be clearly defined. Suppose that an urn contains two different types of coupons: three coupons of type A and four coupons of type B. After Alice draws a coupon out of the urn, the urn is reset to its original state of having seven coupons: three coupons of type A and four coupons of type B (using an unlimited supply of spare coupons). Compute the expected number of draws needed for Alice to collect at least two coupons of each type (at least two of type A and at least two of type B). Do not round your answer to the nearest integer. Hint: If you need to cite basic properties (such as expectation-formula(e)) for certain probability distribution(s) as part of your work, you may do so without proof. Any random variables used should first be clearly defined.