federal law has reserved 100 acres of land to be left unharvested.if the trees grow at a density of 3 trees/100 sq feet, how many trees protected from logging?

Q: Federal law has reserved 100 acres of land to be left unharvested. If the trees grow at a density of 3 trees/100 sq feet, how many trees protected from logging?
1 acre = 43560 sq feet
100 acre = 4356000 sq feet
There are 3 trees per 100 sq feet
3 trees - 100 sq feet
X trees - ...