How many currencies are used in places where people speak French?
SELECT DISTINCT COUNT(?uri) WHERE { ?x <http://dbpedia.org/ontology/officialLanguage> <http://dbpedia.org/resource/French_language> . ?x <http://dbpedia.org/ontology/currency> ?uri  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Currency>}
French_language