The area covered by the shadow is given by:
A = (512,000,000) * (0.9 / 100)
A = 4,608,000
Then, since the area is a rectangle we have:
A = (w) * (l)
Where,
w: width
l: long
Substituting we have:
4,608,000 = (w) * (14,500)
Clearing w we have:
w = (4,608,000) / (14,500)
w = 317.7931034
Round to the nearest kilometer:
w = 318 Km
Answer:
The width of such a rectangle would be:
A: 318km