Waves Questions

Two cars moving in opposite directions approach each other with speed of $22\text{m/s}$ and $16.5\text{m/s}$ respectively. The driver of the first car blows a horn having a frequency $400\text{Hz}$. The frequency heard by the driver of the second car is [velocity of sound $340\text{m/s}$ ]:

The two nearest harmonics of a tube closed at one end and open at other end are $220\text{Hz}$ and $260\text{Hz}$. What is the fundamental frequency of the system?