The answer to this is 0.29 M of the acid. The things that you should look for when trying to compute are the “clues” or the details that will let you know what formula to use. In this case, there are a lot of details that are not given.
The best way to do is to assume the type of information that you will use. Assume that the ratio of the given information is 1:1.
The best equation to use for this is the volume of acid multiplied by the molarity of acid. This will be equal to the volume of the base multiplied by the molarity of the base. When you do this, you will get the answer 0.29 M.
Since the name of the acid (and the equation) is not given, you must assume that it is a 1:1 ratio. Use equation:
volume of acid x molarity of acid = volume of base x molarity of base (when the ratio is 1:1).