Question

please try to answer my question:
John drove for 3 hours at a rate of 50km/h and 2 hours at 60 km/h. what was his average speed for the whole journey?

Answer 1

Here is your answer:

Answer 2

Explanation:

QUESTION:

John drove for 3 hours at a rate of 50km/h and 2 hours at 60 km/h. what was his average speed for the whole journey?

SOLUTION:

Case-I:

time taken = 3hrs

speed acquired = 50km/hr

∴ distance covered

= speed acquired × time taken

= (50 × 3)km

= 150km

Case-II:

time taken = 2hrs

speed acquired = 60km/hr

∴ distance covered

= speed acquired × time taken

= (60 × 2)km

= 120km

Total time taken in the whole journey

= (3+2)hrs = 5hrs

Total distance covered in the whole journey

= (150+120)km = 270km

∴ average speed for the whole journey

$= \frac{total \: distance \: covered}{total \: time \: taken} \\ = \frac{270}{5} km/hr \\ = 54km/hr$

HENCE, the average speed for the entire journey is 54km/hr.