A 5-pack of batteries costs $2.70. What is the unit price?
per battery

For a read-a-thon, jay and odhràn each started reading a book at the same time and continued reading for several hours. jay's book had 278 pages, and he read 55 pages per hour. odhràn's book had 238 pages, and he read 45 pages per hour. after how many hours did they have the same number of pages left, and how many pages were left?

Is it true or false i’m trying to pass this test so i can leave school

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.