How many apple trees can be planted in an area of 0.8 square kilometers with a row spacing of 5 meters and a plant spacing of 4 meters?

How many apple trees can be planted in an area of 0.8 square kilometers with a row spacing of 5 meters and a plant spacing of 4 meters?


0.8 sq km = 800000 sq m
800000 (5 × 4) = 40000