instruction:
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.
question:
Passage: Imperial College Healthcare NHS Trust was formed on 1 October 2007 by the merger of Hammersmith Hospitals NHS Trust (Charing Cross Hospital, Hammersmith Hospital and Queen Charlotte's and Chelsea Hospital) and St Mary's NHS Trust (St. Mary's Hospital and Western Eye Hospital) with Imperial College London Faculty of Medicine. It is an academic health science centre and manages five hospitals: Charing Cross Hospital, Queen Charlotte's and Chelsea Hospital, Hammersmith Hospital, St Mary's Hospital, and Western Eye Hospital. The Trust is currently the largest in the UK and has an annual turnover of 800 million, treating more than a million patients a year.[citation needed]
answer:
what hospitals were formed from Imperial College Healthcare?

question:
Passage: To be considered 'enriched', the uranium-235 fraction should be between 3% and 5%. This process produces huge quantities of uranium that is depleted of uranium-235 and with a correspondingly increased fraction of uranium-238, called depleted uranium or 'DU'. To be considered 'depleted', the uranium-235 isotope concentration should be no more than 0.3%. The price of uranium has risen since 2001, so enrichment tailings containing more than 0.35% uranium-235 are being considered for re-enrichment, driving the price of depleted uranium hexafluoride above $130 per kilogram in July 2007 from $5 in 2001.
answer:
Between what percent fraction range of uranium-235 is uranium regarded as unenriched?

question:
Passage: The original idea of a Chinese satellite navigation system was conceived by Chen Fangyun and his colleagues in the 1980s. According to the China National Space Administration, the development of the system would be carried out in three steps:
answer:
Who first came up with the idea for a Japanese satellite navigation system?