TASK DEFINITION: This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
PROBLEM: In addition to those actors who have headlined the series, others have portrayed versions of the Doctor in guest roles. Notably, in 2013, John Hurt guest-starred as a hitherto unknown incarnation of the Doctor known as the War Doctor in the run-up to the show's 50th anniversary special "The Day of the Doctor". He is shown in mini-episode "The Night of the Doctor" to have been retroactively inserted into the show's fictional chronology between McGann and Eccleston's Doctors, although his introduction was written so as not to disturb the established numerical naming of the Doctors. Another example is from the 1986 serial The Trial of a Time Lord, where Michael Jayston portrayed the Valeyard, who is described as an amalgamation of the darker sides of the Doctor's nature, somewhere between his twelfth and final incarnation.

SOLUTION: Who played the War Doctor?

PROBLEM: Recently, the Air Force refined its understanding of the core duties and responsibilities it performs as a Military Service Branch, streamlining what previously were six distinctive capabilities and seventeen operational functions into twelve core functions to be used across the doctrine, organization, training, equipment, leadership, and education, personnel, and facilities spectrum. These core functions express the ways in which the Air Force is particularly and appropriately suited to contribute to national security, but they do not necessarily express every aspect of what the Air Force contributes to the nation. It should be emphasized that the core functions, by themselves, are not doctrinal constructs.

SOLUTION: How many core functions did the Air Force reduce its duties down to recently?

PROBLEM: Outstanding debts were also agreed and the company permitted to export 250 tons of saltpetre. Again in 1673, Banks successfully negotiated another contract for 700 tons of saltpetre at 37,000 between the king and the company. So urgent was the need to supply the armed forces in the United Kingdom, America and elsewhere that the authorities sometimes turned a blind eye on the untaxed sales. One governor of the company was even reported as saying in 1864 that he would rather have the saltpetre made than the tax on salt.

SOLUTION:
Due to agreed debt what 250 tons product was first permitted to be exported by the company after the seven years' war?