Question: How many rivers end in the Indian Ocean?
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT COUNT(?uri) WHERE {?uri onto:riverMouth <http://dbpedia.org/resource/Indian_Ocean>  . ?uri rdf:type onto:River}