How many {wing configuration} are to/by {fixed-wing aircraft} ?
A fixed-wing aircraft contains how many wing configurations?
How many wing configurations are on a fixed-wing aircraft?
SELECT ( COUNT ( ?i ) AS ?o ) { ?i property:wing_configuration resource:fixed-wing_aircraft }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1654> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q2875704 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P1654 wd:Q2875704 }
3