In this task you will be given an answer to a question. You need to generate a question. The answer given should be a correct answer for the generated question.

Let me give you an example: This list contains the top 25 accounts with the most followers on the social photo-sharing platform Instagram. As of May 2018, the most followed user is Instagram's own account, with over 235 million followers. Selena Gomez is the most followed individual, with over 137 million followers. Ten accounts have exceeded 100 million followers on the site.
The answer to this example can be: who has the maximum number of followers on instagram
Here is why: The answer is talking about the Instagram accounts that have the most followers. The question asking about the maximum number of followers. So this is a good example.

OK. solve this:
Egyptologists believe the pyramid was built as a tomb for the Fourth Dynasty Egyptian pharaoh Khufu (often Hellenized as 'Cheops') and was constructed over a 20-year period. Khufu's vizier, Hemiunu (also called Hemon) is believed by some to be the architect of the Great Pyramid. It is thought that, at construction, the Great Pyramid was originally 280 Egyptian Royal cubits tall (146.5 metres (480.6 ft)), but with erosion and absence of its pyramidion, its present height is 138.8 metres (455.4 ft). Each base side was 440 cubits, 230.4 metres (755.9 ft) long. The mass of the pyramid is estimated at 5.9 million tonnes. The volume, including an internal hillock, is roughly 2,500,000 cubic metres (88,000,000 cu ft).
Answer:
who built the great pyramid of giza and why