Question

What is the volume of stock solution of 51 g/L AgNO3 required to make a 50 mL solution of 0.03 M final concentration?

Answer 1

How many moles do you need for the final solution? That is M x L = moles = 0.03M x 0.050L = ?

So you need ? moles AgNO3. How many grams is that? That is g = moles x molar mass = x grams.

So your solution is 51 g/L. How many L must you take to arrive at x grams. That will be 51 g/L x yL = x grams.
Solve for yL. You have a number for x grams.