Question

A car covers a distance of 4 km in 6 minutes. If it's speed is decreased by 2 km/hr, then find the time taken by the car to cover same distance.
1. 120/19 min
2. 2/19 min
3. 45 min
4. 60/19 min

Answer 1

Correct Answer - Option 1 : 120/19 min

Given:

Distance = 4 km

Time = 6 minutes

Formula:

Distance = Speed × Time

Speed = Distance/Time 

Calculation:

Time = 6 minutes

⇒ Time = (6/60) hr = (1/10) hr

⇒ Speed = Distance/Time = 4/(1/10)

⇒ Speed = 40 km/hr

According to question,

If its speed is decreased by 2 km/hr

⇒ New speed = (40 - 2) km/hr = 38 km/hr

Time taken by the car to cover same distance,

Time = Distance/Speed

⇒ Time = (4/38) hr = (4/38) × 60 = 120/19 minutes

∴ The time taken by the car to cover same distance is 120/19 minutes.