Answer: 50mL
Explanation: This is solved just like you'd solve a proportion in mathematics. But first, you need to make your temperature values have the same units. It is ideal to have both units in K almost 90% of the time. So to convert the values, you'll add 273 to your Celsius temperature: 27. This gives you 300. Then, you set 300K/25mL = 600K/?. We see that to get from 300 to 600, we just double our values. Therefore, we'll do the same to the 25mL. This gives us 50mL.
I hope this helps!