Correct Answer - Option 2 : 22.5 kmph

**Given:**

Speed for 50 km distance = 25 kmph

Speed for 40 km distance = 20 kmph

**Formula Used:**

Average Speed = Total Distance/Total Time

**Calculations:**

Speed for 50 km distance = 25 kmph

Speed for 40 km distance = 20 kmph

Total distance = (50 + 40) km

⇒ Total distance = 90 km

Total Time = (50/25) + (40/20)

⇒ Total Time = (2 + 2) hrs. = 4 hrs.

Average Speed = Total Distance/Total Time

⇒ Average Speed = 90/4 = 22.5kmph

**∴ The average speed for the whole journey is 22.5 kmph.**