3) Shruti is asked by her school Principal to prepare a list of students who have appeared in the National Cyber Olympiad Test. Which Function you will suggest her to calculate number .​

Im doing this last minute and literally none of my neighbors or people that my dad works with use excel so if anyone could me make up an example

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)?

What is one reason why indoor air pollution has become an increasing problem.