To solve this we use the
equation,
M1V1 = M2V2
where M1 is the concentration of the stock solution, V1 is the
volume of the stock solution, M2 is the concentration of the new solution and
V2 is its volume.
12.3(V1) = (1.2)(12.4 L)
V1 = 1.21 L needed of the stock solution
