Keith bought 5 new baseball trading cards to add to his collection. The next day his dog ate half of his collection. There are now only 40 cards left. How many cards did Keith start with?

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?

He concluded that a heavier object dropped from the same height as a lighter object will land

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).