What is the expected number of jacks-or-better cards in a five-card hand?

Q13 what function does a security certificate perform? a. creates user accounts b. scrambles data c. identifies users d. creates password policies e. provides file access

After you present a proposal, the committee starts asking you questions, some beyond the strict focus of your proposal. they ask questions about implications in other fields and knowledge about other fields. you are asked to redo your proposal. what is most likely missing? breadth of material depth of material clarity of material details of material

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?