3. How much of his empire's wealth did Qin Shi Huangdi spend on preparations for his afterlife and why did he devote so much wealth to the afterlife?

One-third of the nations income.

Explanation:

1. Quo Shi Huang was widely known as the first emperor of China. His reign as the emperor lasted for thirty-five years. The period is around 246 to 210 BC. During his time, he spends so much empire's wealth on the preparation for the afterlife.

He constructed an expensive personal tomb for himself, and a mausoleum for soldiers to protect him in the afterlife.

The mausoleum housed about 8,000 soldiers, 130 chariots, and 670 horses. It was believed to have cost about "one-third of the nation's income."

2. Due to his constant fear of death, he sought the elixir of life to give him immortality. However, he considered that should he not find the key to immortality, he will need protection in the afterlife.