A person moved from place A for place B at 2 p.m. at a speed of 4.5 km/h, stayed at place B for 1.5 hours and returned to place A at a speed of 6 km/h. He came back to place A at 7 p.m. What is the distance between places A and B (in km)?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 9
Distance = speed × time
Let ' y ' km be the distance from A to B
His total time of travelling = 5 - 1.5 = 3.5 hours (Since he took a rest of 1.5 hours)
Now,
Time taken to travel from A to B/Ttime taken to travel from B to A = Speed from B to A/Speed from A to B (speed and time are inversely proportional)
Time taken to travel from A/Ttimetaken to travel from B = 6/4.5
⇒ 4/3
Time taken to travel from A to B = (4/7) × 3.5 = 2 hours
Time taken to travel from B to A = (3/7) × 3.5 = 1.5 hours
Total distance = 4.5 × 2 = 9km