Julie dissolved 20 g of sugar in a cup of water. The mass of the solution was 500 g. What volume of water did Julie start with?

well, the water was 480 g, so that's 480mL.

To find the volume of water that Julie started with, we need to subtract the mass of the sugar from the total mass of the solution.

The mass of the sugar that Julie dissolved in the water is 20 g.

The total mass of the solution is 500 g.

So, the mass of the water can be found by subtracting the mass of the sugar from the total mass of the solution:

Mass of water = Total mass of the solution - Mass of the sugar
Mass of water = 500 g - 20 g
Mass of water = 480 g

Now, we need to convert the mass of the water to its volume. Since we know that the density of water is 1 g/cm³, we can use the following formula to convert mass to volume:

Volume = Mass / Density

In this case, the mass of water is 480 g and the density of water is 1 g/cm³, so:

Volume of water = Mass of water / Density of water
Volume of water = 480 g / 1 g/cm³
Volume of water = 480 cm³

Therefore, Julie started with 480 cm³ of water.