In which material do you think light rays travel faster-glass or air?

Light rays travel faster in air, because the speed of light in an optically rarer medium is more than the speed of light in a denser medium. And, in this case, the air is an optically rarer medium and glass is a denser medium. Hence, light rays will travel fast in the air.

Explanation

The angle of refraction or the amount of bending of light depends on the refractive index  of the two media.

1. When light passes through a low refractive index, like air (faster medium or optically rarer medium) to a high refractive index, like glass(slower medium or optically denser medium), its speed decreases and bends towards the normal. 

2. When light passes through a high refractive index, like glass (slower medium or optically denser medium) to a low refractive index, like air (faster medium or optically rarer medium) its speed increases and bends away from the normal.