Ronald is calculating the density of oranges in a crate. He knows the number of oranges in the crate and the volume of the crate. Which of the following formulas can be used to calculate the density of oranges in the crate?

Density = volume of crate over number of oranges
Density = number of oranges over volume of crate
Volume of crate = density over number of oranges
Number of oranges = density over volume of crate