The rule that we will use to solve this question is:
(M*V)1 = (M*V)2 where:
M is the molarity and V is the volume
We are given that:
M1 = 18 m
M2 = 0.125 m
V2 = 1.8 l
we need to find V1
So, we will just substitute in the above equation to get V1 as follows:
18(V1) = 0.125(1.8)
V1 = 0.0125 liters