Rohit travels from point A to point B at the speed of 16 km/hr and reaches…
2025
Rohit travels from point A to point B at the speed of 16 km/hr and reaches point B at 3 p.m. He will reach point B at 2 p.m. if he travels at an average speed of 20 km/hr. At what average speed (in km/hr) should Rohit travel to reach point B at 1 p.m.?
- A.
26 2/3
- B.
22
- C.
18
- D.
40
Attempted by 43 students.
Show answer & explanation
Correct answer: A
Step-by-Step Solution
Understand the Relationship: Since the distance between point A and point B is constant, the product of speed and time must be equal for different scenarios (Distance = Speed × Time). Let the distance be D and the time taken at 16 km/hr be t hours.
Set up the Equations:
Scenario 1: At 16 km/hr, time = t. So, D = 16 × t.
Scenario 2: At 20 km/hr, he reaches 1 hour earlier (3 p.m. to 2 p.m.), so time = t - 1. So, D = 20 × (t - 1).
Solve for t:
16t = 20(t - 1)
16t = 20t - 20
4t = 20
t = 5 hours.
Find the Distance (D):
D = 16 km/hr × 5 hours = 80 km.
Calculate Required Speed:
To reach at 1 p.m. (which is 2 hours earlier than 3 p.m.), the time taken should be t - 2 = 5 - 2 = 3 hours.
Required Speed = Distance / Required Time = 80 km / 3 hours = 26 and 2/3 km/hr.