tag:blogger.com,1999:blog-15628310.post114285438303965677..comments2021-04-22T08:14:35.383-04:00Comments on Question of the day: Reading time!Anonymoushttp://www.blogger.com/profile/18153935609499338685noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-15628310.post-1142946883048429932006-03-21T08:14:00.000-05:002006-03-21T08:14:00.000-05:00I suppose the mailman could be his father... ;-)Fo...I suppose the mailman could be his father... ;-)<BR/><BR/>For each father-son couple holds: the father bought x books of x dollars, the son bought y books of y dollars. The difference between their expenses is 21 dollars, thus x^2 - y^2 = 21.<BR/>Since x and y are whole numbers (each book costs a whole amount of dollars), there are two possible solutions: (x=5, y=2) or (x=11, y=10). Because the difference between Alex and Peter is 5 books, this means that father Alex bought 5 books and son Peter 10. This means that the other son, Tim, bought 2 books, and that his father is Alex.Anonymoushttps://www.blogger.com/profile/18153935609499338685noreply@blogger.comtag:blogger.com,1999:blog-15628310.post-1142885016947861582006-03-20T15:03:00.000-05:002006-03-20T15:03:00.000-05:00THe mailmanTHe mailmanDarvhttps://www.blogger.com/profile/09533799179860083881noreply@blogger.com