What travels faster : a radio signal or sound in air ?

Explanation

A radio signals travels with the speed of light which is `3 xx 10^8 m//s`. On the other hand, sound travels in air with a speed of about `340 m//s`. Roughly speaking, a radio signal travels `(3 xx 10^8 m//s)//(340 m//s) ~~ 10^6`, i.e., a million times faster than sound in air.