A highly reflective mirror reflects 95% of the light that falls on it. In a light box having walls made of the mirror, the light reflects back-and-forth between the mirrors. 

(a) If the original intensity of the light is I₀ before it falls on a mirror, write the nth term of the sequence that describes the intensity of the light after n reflections. 

(b) How many reflections are needed to reduce the light intensity by at least 98%?