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Car A and car B set off from the same point to travel the same journey. Car A sets off three minutes before car B. If car A travels at 60 km/h and car B travels at 70 km/h, how many kilometres from the starting point will the two cars draw level?​

User ShivamD
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1 Answer

7 votes

Answer:

Let's start by calculating how much of a head start Car A has in distance before Car B starts.

In 3 minutes, Car A will have travelled:

d = r * t = (60 km/h) * (3/60) h = 3 km

So when Car B starts, Car A is 3 km ahead.

Now let's consider the time it takes for both cars to meet. Let's call the time it takes for both cars to meet t.

During that time, Car A will travel at a speed of 60 km/h, and Car B will travel at a speed of 70 km/h.

The distance that Car A will travel during that time is:

dA = 60 km/h * t

The distance that Car B will travel during that time is:

dB = 70 km/h * t

The total distance between the two cars when they meet is:

d = dA + dB

We want to find the value of t that makes dA + dB = 3 km (the distance that Car A is ahead of Car B when Car B starts).

Substituting the expressions for dA and dB, we get:

60 km/h * t + 70 km/h * t = 3 km

Simplifying, we get:

130 km/h * t = 3 km

t = 3 km / 130 km/h

t = 0.0231 h

Now we can calculate the distance that both cars will have travelled when they meet:

dA = 60 km/h * 0.0231 h = 1.38 km

dB = 70 km/h * 0.0231 h = 1.61 km

d = dA + dB = 1.38 km + 1.61 km = 2.99 km

Therefore, the two cars will draw level after travelling approximately 2.99 km from the starting point.

User DarkFenix
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