Apublisher wants to figure out how thick their new book will be. the book has a front cover and a back cover, each of which have a thickness of 1/4 of an inch. they have a choice of which type of paper to print the book on. bond paper has a thickness of 1/4 inch per one hundred pages. write an equation for the width of the book, y, if it has x hundred pages, printed on bond paper. ledger paper has a thickness of 2/5 inch per one hundred pages. write an equation for the width of the book, y, if it has x hundred pages, printed on ledger paper. if they instead chose front and back covers of thickness 1/3 of an inch, how would this change the equations in the previous two parts?

Aprisoner is trapped in a cell containing three doors. the first door leads to a tunnel that returns him to his cell after two days of travel. the second leads to a tunnel that returns him to his cell after three days of travel. the third door leads immediately to freedom. (a) assuming that the prisoner will always select doors 1, 2 and 3 with probabili- ties 0.5,0.3,0.2 (respectively), what is the expected number of days until he reaches freedom? (b) assuming that the prisoner is always equally likely to choose among those doors that he has not used, what is the expected number of days until he reaches freedom? (in this version, if the prisoner initially tries door 1, for example, then when he returns to the cell, he will now select only from doors 2 and 3.) (c) for parts (a) and (b), find the variance of the number of days until the prisoner reaches freedom. hint for part (b): define ni to be the number of additional days the prisoner spends after initially choosing door i and returning to his cell.