Need help with this word problem ! Appreciate it a lot!

Question

A body's weight varies inversely with the square of its distance from the center of the earth: if a chicken weighs 12 pounds when it is 5,000 miles from the earth's center, how much will the chicken weigh when it is 10,000 miles from the earth's center?

A) 48 pounds

B) 24 pounds

C) 6 pounds

D) 3 pounds

E) None of those

Answer 1

Weight, W = G/d² where G is some gravity constant.

For 5,000 miles, 12 = G/(5000)², so G = 12×5000²

For 10000 miles

W = 12(5000)²/(10000)² = 12(5000/10000)² = 12(1/2)² = 12/4 = 3 pounds

Answer (D)