How many {powerplant} are for {Airbus A320} ?
What is the number of engines on the Airbus A320?
How many engines does the Airbus A320 have ?
SELECT ( COUNT ( ?k ) AS ?a ) { resource:Airbus_A320_family property:powered_by ?k }
SELECT (COUNT(?obj) AS ?objs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q6475> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P516> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
} 

SELECT (COUNT(?obj) AS ?value ) { wd:Q6475 wdt:P516 ?obj }
4