How many {has active ingredient} are to/by {epinephrine} ?
What number of ingredients does it take to make epinephrine?
How many active ingredients make up epinephrine?
SELECT ( COUNT ( ?n ) AS ?f ) { ?n property:has_active_ingredient resource:epinephrine }
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/P3781> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q132621 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P3781 wd:Q132621 }
5