Correct Answer - Option 3 : 18

**Concept:**

Average Speed = Total Distance/Total time

**Calculation:**

A man travels first 50 km at 25 kmph

Time taken to travel 50 km = 50/25 = 2 hours

Next 40 km at 20 kmph and,

Time taken to travel 40 km = 40/20 = 2 hours

Last 90 km at 15 kmph

Time taken to travel 90 km = 90/15 = 6 hours

Total distance = 180 km

Total time = 10 hour

Average speed = 180/10 = 18 km/hr

∴ His average speed for the whole journey (in Kmph) is 18 km/hr