What fraction of ice should fill the cup?

• A. 1/2
• B. 2/3
• C. 3/4
• D. 1

Answer: (B)

The main idea is getting the ice level just right so there’s enough space for the beverage while still keeping the drink cold. Filling the cup with ice to two-thirds of its height leaves about one-third of the cup for the drink itself. This balance helps prevent spills when picking up or carrying the cup and ensures the drink has room for the liquid instead of overflowing into the ice.

If you only filled half the cup with ice, there wouldn’t be enough space for the beverage, increasing the chance of spilling or overflowing. Going up to three-quarters would leave too little room for the drink, making spills and a weaker-tasting beverage as the ice melts and takes up more space. Filling to the top with ice leaves no room for the drink at all.

So, two-thirds ice keeps the cup cold and stable while leaving the proper space for the drink.