I want to talk to a girl

Find three consecutive numbers such that the sum of one-fourth the first and one-fifth the second is five less than one-seventh the third

The head librarian at the library of congress has asked her assistant for an interval estimate of the mean number of books checked out each day. the assistant provides the following interval estimate: from 740 to 920 books per day. what is an efficient, unbiased point estimate of the number of books checked out each day at the library of congress?

Suppose i flip two identical coins. what is the probability that i get one head and one tail?