P1 = Place of accident, Remaining distance = (x + 300) km P2 = Imaginary place of accident, Remaining distance = x km At point P1 for distance (x + 300) km Speed
1
6
↓Time
1
5
↑ ∴ Usual time required for distance (x+300)km=5×2=10h At point P2, for distance xkm Speed
1
6
↓Time
1
5
↑=1h ∴ Usual time required for distance xkm=5×1=5h ∴ Time required to cover 300km=5h ∴ Speed =