Zeeshan travels 294 km at 42 km/hr, the next 210 km at 30 km/hr and the next 330 km at 66 km/hr. What is his average speed (in km/hr) for the whole journey? (Round off your answer to two decimal places)

Correct option is B

Given:

Distance₁ = 294 km, Speed₁ = 42 km/hr

Distance₂ = 210 km, Speed₂ = 30 km/hr

Distance₃ = 330 km, Speed₃ = 66 km/hr

Find average speed.

Formula Used:

Average Speed = $$\frac{D_1 + D_2 + D_3}{\frac{D_1}{S_1} + \frac{D_2}{S_2} + \frac{D_3}{S_3}}$$​​

Solution:

Total distance:

= 294 + 210 + 330 = 834 km

Total time:

T₁ = $$\frac{294}{42}$$​ = 7 hr

T₂ = $$\frac{210}{30}$$​ = 7 hrs

T₃ = $$\frac{330}{66}$$​= 5 hrs

Total time = 7 + 7 + 5 = 19 hr

Average speed:

= $$\frac{834}{19}$$​ = 43.89 km/hr