Two buses A and B are moving in opposite direction. Now if the first bus A moves towards east with a speed of 36 Kmh and bus B moves towards west with a speed of 18 Km/h then the bus B appears to A as
1
moving with a speed of 5 m/s from east to west
2
moving with a speed of 15 m/s from west to east
3
moving with a speed of 15 m/s from east to west
4
moving with a speed of 10 m/s from east to west