what is the relationship between ice in a drink and the amount of water that subsequently gets melted in to it. I'm talking short term, say 3 or 4 minutes, before much melting has occurred.

For example you get a cola with 2 ice cubes and one with 20, would the one with 20 ice cubes stay cooler for longer thus diluting your drink less, or would the one with less ice be less watery because there was less ice to begin with?