The correct numbers to the significant digits are:
[tex] \frac{485.60}{0.78} = 622.56[/tex]g/ml
[tex] 2.09 \times 0.2 = 0.42[/tex]g
[tex] \frac{396.0}{0.85 } = 465.88[/tex]g/ml
Grams(g) is used for the measurement of mass while milliliters(ml) is used for the measurement of volume of liquids.
The above answers are in two significant digits which are the figures that are meaningful in terms of accuracy.
Learn more about significant digits here:
https://brainly.com/question/24491627