Correct Answer - Option 3 : 10 minutes

**Given:**

Speed of bus excluding stoppage = 54 km/hr

Speed of bus including stoppage = 45 km/hr

**Formula used:**

Speed = distance/time

**Calculation:**

Loss in speed when including stoppage = 54 - 45 = 9 km/hr

In 1 hour, bus covers 9 km less due to stoppage

Hence,

Time in which the bus stop per hour = Time taken to cover 9 km.

Time = Distance/speed

⇒ Time = 9/54

⇒ Time = 1/6 hour

⇒ Time = (1/6) × 60 minutes = 10 minutes

**∴ 10 minutes the bus stop per hour **