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67.5% of the 540 km road between the two cities is paved, while the rest is unpaved. the average speed of the car on paved roads was 25 km/h higher than on unpaved roads. find the speed of the car on a paved road if it took 10 hours to cover the entire road​

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Answer: Let's start by finding out the distance covered on paved and unpaved roads respectively.

Distance covered on paved road = 67.5% of 540 km = 0.675 x 540 = 364.5 km

Distance covered on unpaved road = 32.5% of 540 km = 0.325 x 540 = 175.5 km

Let the speed of the car on unpaved roads be x km/h. Then, the speed of the car on paved roads will be (x + 25) km/h.

Now, let's use the formula:

time = distance / speed

We know that the total time taken to cover the entire road is 10 hours.

So,

time taken on paved road + time taken on unpaved road = 10

or,

364.5 / (x + 25) + 175.5 / x = 10

Simplifying this equation, we get:

7.29x + 182.25 = 10x + 725

2.71x = 542.75

x ≈ 200

Therefore, the speed of the car on unpaved roads is 200 km/h, and the speed of the car on paved roads is 225 km/h (x + 25).

Explanation:

User Sanjay
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