John covers a part of the journey at 20 $k m / h r$ and the remaining at 70 $k m / h r$ , taking total of 8 hours to cover the distance of 400 km. How many hours he has been driving at 20 $k m / h r$ ?

2 hours

No worries! We‘ve got your back. Try BYJU‘S free classes today!

3 hours 20 minutes

No worries! We‘ve got your back. Try BYJU‘S free classes today!

4 hours 40 minutes

No worries! We‘ve got your back. Try BYJU‘S free classes today!

3 hours 12 minutes

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D
3 hours 12 minutes

Let the total time he travelled with a speed of 20 kmph is t hours.

So, for (8-t) hours, he travelled at 80 kmph.

As per the question, 20t + 70(8-t) =400

$\Rightarrow 50 t = 160$

$\Rightarrow t = 3.2 h = 3 h 12 m i n$

Suggest Corrections

Similar questions

Q. John covers a part of the journey at 20 km/hr and the remaining at 70 km/hr, taking total of 8 hours to cover the distance of 400 km, How many hours he has been driving at 20 km/hr?

Rahul covers a part of the journey at 20 km/hr and the remaining at 70 km/hr, taking total of 8 hours to cover the distance of 410 km. How many hours he has been driving at 20 km/hr?

Q. Vijay covers a part of the journey at 20 km/h and the remaining at 10 km/h, taking a total of 3 hours to cover a distance of 50 km. For how many hours did he drive at a speed of 20 km/h?

Q. A person drives his car for

3

hours at a speed of

40

km/hr and for

4.5

hours at a speed of

60

km/hr. At the end of it, he finds that he was covered

\frac{3}{5}

of the total distance. What is the uniform speed with which he should further drive to cover the remaining distance in

4

hours?

Q. A part of a journey is covered in

1

hour

40

minutes at

75

km/hr and the remaining part of it is covered in

2

hours

50

minutes at

60

km/hr. Find the total length of the journey.

Join BYJU'S Learning Program

John covers a part of the journey at 20 km/hr and the remaining at 70 km/hr , taking total of 8 hours to cover the distance of 400 km. How many hours he has been driving at 20 km/hr?

The correct option is D 3 hours 12 minutes Let the total time he travelled with a speed of 20 kmph is t hours. So, for (8-t) hours, he travelled at 80 kmph. As per the question, 20t + 70(8-t) =400 ⇒50t=160 ⇒t=3.2 h=3 h12 min

John covers a part of the journey at 20 $k m / h r$ and the remaining at 70 $k m / h r$ , taking total of 8 hours to cover the distance of 400 km. How many hours he has been driving at 20 $k m / h r$ ?

The correct option is D
3 hours 12 minutes

Let the total time he travelled with a speed of 20 kmph is t hours.

So, for (8-t) hours, he travelled at 80 kmph.

As per the question, 20t + 70(8-t) =400

$\Rightarrow 50 t = 160$

$\Rightarrow t = 3.2 h = 3 h 12 m i n$