WolframAlpha

Wolfram Alpha is an answer engine developed by Wolfram Research. It is an online service that answers factual queries directly by computing the answer from externally sourced data, rather than providing a list of documents or web pages that might contain the answer. 

Wolfram Alpha, which was released on May 15, 2009, is based on Wolfram's earlier flagship product Mathematical, a computational platform or toolkit that encompasses computer algebra, symbolic and numerical computation, visualization, and statistics capabilities 

Alpha differs from semantic search engines, which index a large number of answers and then try to match the question to one. 

Wolfram Alpha gives results based on computational facts. It is capable of responding to particularly phrased fact-based questions such as "Where was Benito Perez Galdos born?" or more complex questions such as "How old was President Barack Obama in 1974?" and generate a human-readable answer.

Here is the link to access http://www.wolframalpha.com/