A man is located between two tall buildings, P and Q. He is $50\,\text{m}$ from P and $200\,\text{m}$ from Q. He sounds a horn. The first echo he hears comes from building P, and then $1.0\,\text{s}$ later he hears the first echo from building Q. What speed of sound is obtained from this information?
- A$250\,\text{m s}^{-1}$
- B$300\,\text{m s}^{-1}$
- C$330\,\text{m s}^{-1}$
- D$500\,\text{m s}^{-1}$