Question 60
On a sunny day a sphere rests on a horizontal ground. At a certain instant the shadow of the sphere reaches a distance of 10 meters from the point where the sphere touches the ground. At the same instant a rod of length 1 meter placed vertically on the ground casts a shadow 2 meters long. What is the radius of the sphere in meters?
(A) $\frac{5}{2}$
(B) $9-4 \sqrt{5}$
(C) $10 \sqrt{5}-20$
(D) $8 \sqrt{10}-23$
(E) $6-\sqrt{15}$.
(A) $\frac{5}{2}$
(B) $9-4 \sqrt{5}$
(C) $10 \sqrt{5}-20$
(D) $8 \sqrt{10}-23$
(E) $6-\sqrt{15}$.