Answer:
it requires 280 ton of wood
Explanation:
one ship can accommodate 300 sailors so for 2100 sailors you need
2100/300
7 ships
and as I ship require 40 tons of wood then 7*40
280 tons
then
he can get 4 ton of wood per day
then
280/4
70 days
therefore he needs wood for 70 days to accommodate 2100 sailors