What volume of a product is required to make half liter of 0.25% of the product solution?

Answer:
0.00125 liters of product
Explanation:
So the question it tell you that 0.25 % from 0.5 liters is pure product.
So we calculate the volume of pure product:
volume = (0.25 / 100) × 0.5 = 0.00125 liters
Now to produce the solution over 0.00125 liters of pure product you add (most likely) water until you reach a volume of 0.5 liters.