Passage: Some 4.2 million immigrants arrived between 1945 and 1985, about 40 per cent of whom came from Britain and Ireland. The 1957 novel They're a Weird Mob was a popular account of an Italian migrating to Australia, although written by Australian-born author John O'Grady. The Australian population reached 10 million in 1959–with Sydney its most populous city.

Question: How many immigrants arrived?
4.2 million