Question

A car moves with a steady speed of 60 km/hr for 2 hours between two towns A and B. If the average speed of the car for the round trip is 50 km/hr, then compute the speed of the car when it moves from B to A. ​

Answer 1

The speed of the car when it moves from B to A is 40 km/hr.

Step-by-step explanation:

To find the speed of the car when it moves from B to A, we need to consider the average speed for the round trip. The average speed for the round trip is given as 50 km/hr. Since the car moves with a steady speed of 60 km/hr for 2 hours from A to B, we can use the concept of average speed to find the speed from B to A.

Let's assume the speed from B to A as x km/hr. The total distance covered by the car is the same for both the journeys. So, the time taken for the return journey (B to A) is equal to the time taken for the forward journey (A to B).

Using the formula for average speed, (average speed = total distance / total time), the average speed can be calculated as:

50 km/hr = (2 * 60 + 2 * x) / (2 + 2)

Simplifying the equation, we get:

50 = (120 + 2x) / 4

Multiplying both sides by 4, we get:

200 = 120 + 2x

Subtracting 120 from both sides, we get:

80 = 2x

Dividing both sides by 2, we get:

x = 40 km/hr

Hence, the speed of the car when it moves from B to A is 40 km/hr.

Answer 2

The speed of the car when it moves from B to A is approximately 42.86 km/hr.

Step-by-step explanation:

To find the speed of the car when it moves from B to A, we can use the concept of average speed. Average speed is determined by dividing the total distance traveled by the total time taken. In this case, the car travels from A to B with a speed of 60 km/hr for 2 hours, which means the distance between A and B is 60 km/hr x 2 hr = 120 km. Therefore, the distance from B to A is also 120 km.

Now, we know that the average speed for the round trip is 50 km/hr. The total distance for the round trip is 2 x 120 km = 240 km. To find the time taken for the round trip, we divide the total distance by the average speed: 240 km / 50 km/hr = 4.8 hr.

Since the round trip consists of 2 hours from A to B and 2.8 hours from B to A (4.8 hr - 2 hr), we can calculate the speed of the car when it moves from B to A by dividing the distance (120 km) by the time taken (2.8 hr): 120 km / 2.8 hr = 42.86 km/hr.