adjectives and nouns

What is the general rule regarding adjective/noun agreement when an adjective modifies more than one noun and the nouns are of different genders? Thanks, Paul

Vide hoc, Paule: A&G ยงยง286,287
http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0001:part=2:section=3