Note that the prefix milli means one thousandth of the the given base or 0.001 of a certain unit.
So if we have 0.001 liter (L), we may use the prefix milli to re-write is as 1 milliliter (mL).
Hence, the conversion factors of Liter to milliliter and vice-versa are:
(1) 0.001L = 1 mL Or (2) 1 L = 1000 mL
Then, use either of these two conversion factors to convert 0.750L to mL. To do so, express the conversion factor as ratio in such a way that if we multiply it with 0.750L, the unit Liter cancels.
`0.750 L` `*` `(1000mL)/(1 L)` `=` `750 mL`
Hence, 0.750 L = 750 mL.