MathDB
2000 HMMT RMT Geometry #10

Source:

March 3, 2024
geometry

Problem Statement

Let C1C_1 and C2C_2 be two concentric reflective hollow metal spheres of radius RR and R3R\sqrt3 respectively. From a point PP on the surface of C2C_2, a ray of light is emitted inward at 30o30^o from the radial direction. The ray eventually returns to PP. How many total reflections off of C1C_1 and C2C_2 does it take?