Verse 176 of Chapter 4:

People seek your verdict on (the inheritance left by) a childless person. Say, "Allah gives His verdict: if a person dies childless and leaves behind a sister, she shall get half of his inheritance: and if the sister dies childless, her brother shall inherit her property: and if the deceased leaves behind two sisters, they shall inherit two thirds of the inheritance: and if the number of the brothers and sisters is more than two, the share of each brother shall be double that of each sister." Allah makes His Commandments plain to you lest you should go astray; Allah has perfect knowledge of everything.