A man walks at a speed of 9 km/h.  After every km he takes rest for 3 minutes.  How much time will he take to cover a distance of 9 km?

84 minutes

He travelled 9 Km in 1 hour.  Time taken to cover 1 km = \(\frac{60}{9}\) = \(\frac{20}{3}\) minutes

9 km = 9 × \(\frac{20}{3}\) = 60 minutes

Total rest time = 8 × 3 = 24 minutes

Total time = (60 + 24) = 84 minutes