Answer:
C. 20 feet
Step-by-step explanation:
Let x = width
Let y = length
If the length is at least 10 feet longer than the width:
⇒ x + 10 ≤ y
⇒ x ≤ y - 10
If the perimeter is to be no more than 100 ft:
⇒ 2x + 2y ≤ 100
⇒ x + y ≤ 50
⇒ x ≤ 50 - y
Equate the equations for x and solve for y:
⇒ y - 10 = 50 - y
⇒ 2y = 60
⇒ y = 30
Substitute found value of y into one of the inequalities for x:
⇒ x ≤ 30 - 10
⇒ x ≤ 20
Therefore, the maximum possible width of the fence is 20 feet.
