About: http://webisa.webdatacommons.org/54962163

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	The difficulty does not depend on whether problem appeared before or not.
http://www.w3.org/ns/prov#wasQuotedFrom	gmatclub.com