A man covers 270 km partly by bus and partly by car. If he covers \(\frac{1}{3}\) of the distance by bus at 30 km/h and the speed of the car was 45 km/h, the average speed for the whole journey was
1
\(\rm 39\frac{3}{5} km/h\)
2
40 km/h
3
\(\rm 38\frac{4}{7} km/h\)
4
\(\rm 37\frac{1}{2} km/h\)
5
None of these