Ramesh starts from a place J and reaches the place K in 28 hours. He travels 2/5 distance at the speed of 10 km/hr and the remaining distance at the speed of 20 km/hr. What is the distance between J and K?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 400 km.
Let the total distance be x
We know that
Speed = Distance/Time
Time taken by Ramesh to cover 2/5 of the distance = (2x/5)/10
Time taken by Ramesh to cover 3/5 of the distance = (3x/5)/20
⇒ (2x/5)/10 + (3x/5)/20 = 28
⇒ 2x/50 + 3x/100 = 28
⇒ 4x/100 + 3x/100 = 28
⇒ 7x = 2800
⇒ x = 400 km