There are 0.408 grams of sodium fluoride in the toothpaste.
Why?
We know that there is 0.24% of sodium floride in a 170 grams toothpaste tube. Since the only information related to the toothpaste is its mass, we can assume that the 0.24% (concentration) is referring to the mass percent, and we can calculate it using the following equation:

Now, substituting the given information and calculating, we have:


We have that there are 0.408 grams of sodium fluoride in the toothpaste.
Have a nice day!