Correct Answer - Option 2 : 5 m/s

**Given**

A man travels first 50 km at 25 km/h, next 40 km at 20 km/h and then 90 km at 15 km/h.

**Concept used**

Average speed = (Total Distance) / Time taken

**Calculation**

T_{1} = 50/25 = 2 hr

T_{2} = 40/20 = 2 hr

T_{3} = 90/15 = 6 hr

Average speed

⇒ \(\frac{{50\ +\ 40\ +\ 90}}{{2\ +\ 2\ +\ 6}}\)

⇒ 18 km/hr

To convert it into m/s multiply with (5/18)

⇒ 18 × (5/18)

∴ 5 m/s