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,
$\frac32=\frac{220}{8\times3\times d}$
$\implies d=\frac{55}9=6.12$
B. Mahatma Gandhi
i belive this is the answer
Answer:
This stele represents the Neo-babylonian military achievement of building protective walls and a moat around Babylon.
Explanation:
The achievement was important because it protected them from attacks.