Andrew Su, CEO at brokerage Compass Global Markets said the average cost of producing gold in Australia, home to some of the world's biggest gold miners, has jumped from $500 an ounce in 2007 to over $1,000 an ounce this year.
Persons (plural) is a very formal word. We only use it in rather legalistic contexts: [notice in a lift] Any person or persons found in possession of illegal substances will be prosecuted.
American Law and Procedure, Vol 13, page 137, 1910: This word `person' and its scope and bearing in the law, involving, as it does, legal fictions and also apparently natural beings, it is difficult to understand; but it is absolutely necessary to grasp, at whatever cost, a true and proper understanding to the word in all the phases of its proper use ...