Input question: Who was the last British Prime Minister to have served in the forces in World War II?

Output answer: james callaghan

Input question: Which letter is given to the irrational number 2.71828 ? It is widely used in population growth calculations, economics and structural engineering.

Output answer: e

Input question: Who was the main author of the U.S. Declaration of Independence?

Output answer: thomas jefferson

Input question: What instrument consisting basically of a telescope that can be rotated vertically and horizontally on graduated scales was designed for use in land surveying for measuring by triangulation ?

Output answer:
theodolite