Answer:
The Shang Dynasty ended in about 1050 BCE, when conquerors from the state of Zhou invaded the capital and successfully toppled the Shang Dynasty. The Zhou conquerors claimed to overthrow the Shang Dynasty for moral reasons. They said that the Shang king was evil and that heaven no longer wanted him to rule.
Its A mastered my test good luck!
assuming efficiency of each man to dig trench, in one day, for one hour is constant,

so one man, working for one hour in one day can dig 1.5 m
so 8 men, working 3 hours a day and will take, say $d$ number of days and efficiency will be constant. so,
$\frac32=\frac{220}{8\times3\times d}$
$\implies d=\frac{55}9=6.12$