Number of trees on
of the land Joe owns = 250 trees
Total Number of trees on the whole land Joe owns = 
= 1000 trees
Area of land covered with 10 trees = 1000
Area of land covered with 1 tree = 
= 100 square feet
Therefore, Total land covered with 1000 trees = 1000
100
= 100,000 square feet
Since 1 acre = 43560 square feet
So, Total acres of land owned by Joe = 
= 2.29 acre
= 2.3 acre
So, Joe owns 2.3 acres of land.