In this task, you're given a context, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both context and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the context or linked information.

Context: Daxing was renamed Chang'an in year 618 when the Duke of Tang, Li Yuan, proclaimed himself the Emperor Gaozu of Tang. Link Information: born Li Yuan, courtesy name Shude, was the founder of the Tang dynasty of China, and the first emperor of this dynasty from 618 to 626. Answer: 8
How many years did Duke of Tang serve as emperor after renaming Daxing, Chang'an?

Context: Approximately 80% of Utah's 2,817,222 people live along the Wasatch Front, centering on Salt Lake City, Link Information: Salt Lake City is more densely populated than the surrounding metro area with a population density of 1,688.77/sqmi Answer: 1,688.77/sqmi
What is the population density of the city that the majority of Utah's population is centered around?

Context: the following year Mohamed Morsi who is backed by the Muslim Brotherhood won Egypt's first democractic elections. Link Information: served as the fifth President of Egypt, from 30 June 2012  Answer: 30 June 2012 

On what date did Morsi take office?