Your answer is 18 :)
work:
pi(2)d
pi(72)
72/2=36=d
2r=d
36/2=18=r
Answer:

Step-by-step explanation:
we know that
The ratio of soil, manure and leaf mould is 
That means
For every 6 liters of the compost, he use 3 liters of soil
so by proportion
Find how many liters of soil does he use for 72 liters of compost

Answer:
I think 4000 worker and I will be there at some point today and I