Hi, I am taking an intro. to elementary analysis class and so far our class has gone over sups/infs, the axiom stuff, archimedean property and now we are on dense sets. I've been stuck on this problem for a really long time trying to find clues on how to do it online. It goes as: Are the numbers of the form ±m/2100 for m [itex]\in[/itex] N dense? What is the length of the largest interval that contains no such number? The book our class is using is Elementary Real Analysis 2nd ed. by bruckner/thomson. The book is online somewhere if needed. But anyways, I am really lost and a really helpful hint would be most appreciated. Thank you!