Correct Answer - Option 1 : 12.5 hours

**Given:**

Speed of the train in onward journey = v km/hr

Speed of the train in return journey = 4v/3 km/hr

Total halt = 2 hr

Total time = 16 hrs

Total distance = 1200 km

Speed of train in onward journey = 150% of Speed of Car

**Formula Used:**

Distance = Speed × Time

**Calculation:**

Suppose the speed of the train in onward = v km/hr

Speed of train in return = 4v/3 km/hr

According to question –

Total time taken = (16 – 2) hrs

⇒ 14 hrs

Average Speed = (Total Distance)/(Total Time)

⇒ (2V_{1}V_{2})/(V_{1} + V_{2})

⇒ (2 × v × 4v/3)/(v + 4v/3)

⇒ (8v^{2}/3)/(7v/3)

⇒ 8v/7

Average Speed = 1200/14

⇒ 8v/7 = 1200/14

⇒ v = 75 km/hr

The speed of the train in onward = 75 km/hr

According to question –

Suppose the speed of the car is x km/hr

⇒ 75 = 150% of x

⇒ 75 = 3x/2

⇒ x = 50 km/hr

The time taken by car to cover the distance of 625 km = 625/50 hr

⇒ 12.5 hours

**∴ the time taken by the car to cover 625 km is 12.5 hours.**