Final answer:
The ratio of cups of rice to cups of water in the recipe is 3 to 5, which can also be represented as 3:5 or 3/5.
Step-by-step explanation:
The question asks for the ratio of cups of rice to cups of water used in a recipe. To find this ratio, we compare the number of cups of rice to the number of cups of water directly. The recipe calls for 3 cups of rice and 5 cups of water. Therefore, the ratio of cups of rice to cups of water is 3 to 5, which can also be written as 3:5 or ⅓/⅕.