There are two methods you can use to solve this problem.
Since the two solutions neutralize each other then we can use the equation
Substitute the values into the equation.
This is essentially a longer version of method 1 but I find that it works well in actually fostering understanding, rather than just taking the shortcut.
To do this, you first need to find the no. of moles in the solution for which you know both concentration and volume. In this case,
Using the same formula,