There are benefits to answering questions within HupPages but they are not directly related to making money. Also, most questions on HubPages are amongst the community and rarely outrank an ask.com or yahoo answer or similar sites on any search engine.
1) Getting 10 best answers wins you an accolade. This raises your HubberScore and makes your profile more appealing to follow. (More Followers usually leads to more money.
2) Answering questions can be a way to get people to look at your profile and articles.
3) HubPages itself has very little detailed information and Hubbers are your best source for how things work on this site.
4) Questions can be a fun way to interact with the HubPage Community.