Erdős problem 298Does every set A⊆NA \subseteq \mathbb{N} of positive density contain some finite S⊂AS \subset A such that ∑n∈S1n=1\sum_{n \in S} \frac{1}{n} = 1?WorkspaceContinue locallyOpen sourceSign in to contributeOpen this exact Problem, source revision, and authority Repository in Workbench. This handoff does not clone, switch, upload, or execute anything.FilesErdős problem 2985 retained source recordsCanvaspublic previewSource#298→ResultNone→Checks0