The department plans to plant additional oak trees in North Park. How many new oak trees must be planted in North Park…

Let x be the number of new oak trees to be planted in North Park.

From the table, North Park currently has 40 maple trees and 60 oak trees, for a total of 40 + 60 = 100 trees.

After planting x new oak trees:

- The new number of oak trees will be 60 + x.

- The new total number of trees in the park will be 100 + x.

The problem requires the number of oak trees to be 75% of the total number of trees. We can set up an equation to represent this relationship:

60 + x = 0.75(100 + x)

Now, we solve for x:

60 + x = 75 + 0.75x

Subtract 0.75x from both sides:

x - 0.75x = 75 - 60

0.25x = 15

Divide both sides by 0.25:

x = 15 / 0.25

x = 60

So, 60 new oak trees must be planted in North Park.

A is incorrect because it comes from solving 60 + x = 0.75 · 100, which fails to account for the new trees in the total. B is incorrect because it is 75% of the current number of oak trees (0.75 · 60), not the correct proportion. D is incorrect because it is the target number of oak trees in the park (60 + 60), not the number of new trees to be added.