This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Passage: On March 31, 2010, the YouTube website launched a new design, with the aim of simplifying the interface and increasing the time users spend on the site. Google product manager Shiva Rajaraman commented: "We really felt like we needed to step back and remove the clutter." In May 2010, it was reported that YouTube was serving more than two billion videos a day, which it described as "nearly double the prime-time audience of all three major US television networks combined". In May 2011, YouTube reported in its company blog that the site was receiving more than three billion views per day. In January 2012, YouTube stated that the figure had increased to four billion videos streamed per day.
What happened on March 30 2010?

Passage: Uranium carbides and uranium nitrides are both relatively inert semimetallic compounds that are minimally soluble in acids, react with water, and can ignite in air to form U
3O
8. Carbides of uranium include uranium monocarbide (UC), uranium dicarbide (UC
2), and diuranium tricarbide (U
2C
3). Both UC and UC
2 are formed by adding carbon to molten uranium or by exposing the metal to carbon monoxide at high temperatures. Stable below 1800 °C, U
2C
3 is prepared by subjecting a heated mixture of UC and UC
2 to mechanical stress. Uranium nitrides obtained by direct exposure of the metal to nitrogen include uranium mononitride (UN), uranium dinitride (UN
2), and diuranium trinitride (U
2N
3).
Along with uranium monocarbide and uranium dicarbide, what is a unnotable carbide of uranium?

Passage: To the north-east of the Somerset Levels, the Mendip Hills are moderately high limestone hills. The central and western Mendip Hills was designated an Area of Outstanding Natural Beauty in 1972 and covers 198 km2 (76 sq mi). The main habitat on these hills is calcareous grassland, with some arable agriculture. To the south-west of the Somerset Levels are the Quantock Hills which was England's first Area of Outstanding Natural Beauty designated in 1956 which is covered in heathland, oak woodlands, ancient parklands with plantations of conifer and covers 99 square kilometres. The Somerset Coalfield is part of a larger coalfield which stretches into Gloucestershire. To the north of the Mendip hills is the Chew Valley and to the south, on the clay substrate, are broad valleys which support dairy farming and drain into the Somerset Levels.

How much area does the Somerset Coalfield cover?