There is a mistake in the question formulation, there is no way to say what it is really asking. No wonder you have problems solving it.

First phrase was probably intended to say something like "A 5% Dextrose solution is 0.05 (g/mL) Dextrose" or "A 50% Dextrose solution is 0.5 (g/mL) Dextrose."

I wouldn't be so sure AWK's guess is the right one. There are any other possible ones, like: how many grams of Dextrose are needed for making 1.7 L of 5% solution? or: how many grams of 50% Dextrose solution are needed for making 1.7 L of 5% solution? or even: how many grams of Dextrose are needed for making 1.7 L of 0.5% solution? It is quite likely that the target is 5% solution, as this is a common concentration used for IV administration, but the question doesn't state that.