Wolfram | Alpha does not have the capability of parsing arbitrary word problems.
There are at least two technical obstacles. One is the natural language processing (NLP) required in order to parse the problem into blocks that could be processed mathematically. Related is the "chaining problem", wherein one must figure out how one computation gets applied in a later one. It's probably accurate to say that this is really a subset of the NLP aspect.
For more information see e.g.Robots challenged to pass Todai examination
or look up "Todai robot". (Apropos of not much, I overlapped in grad school, and in one course, with the project leader.)