A man travels first 150 km of his journey at 80 km/hr. Due to bad weather he travels the next 150 km of his journey at 60 km/hr. What is his average speed for the first 300 km of his journey?

68.6 Km/hr

Formulae for average speed: \(\frac{2S_1 S_2 }{S_1 + S_2}\) (The formulae is valid only when the distance travelled is same)

Average speed = \(\frac{\text{2 * 80 * 60}}{\text{ 80 + 60}}\)

Average speed = \(\frac{ 9600}{140 }\)

Average speed = 68.57 km/hr