How many {home world} are to/by {Venus} ?
What is the number of home worlds for Venus?
How many home worlds are determined for Venus?
SELECT ( COUNT ( ?m ) AS ?z ) { ?m property:home_world resource:Venus }
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/P1165> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q313 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P1165 wd:Q313 }
3