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sofia drove her car 45 kilometres and she ran out of gas and had to walk 2 kilometres to a gas station. her speed of driving is 15 times speed of walking. if the total time for the drive and walk is 1.5 hrs. what was sofia driving?​

User Tashika
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2 Answers

2 votes

Answer:

Step-by-step explanation:

Let's assume Sofia's walking speed is W km/h. According to the given information, her driving speed is 15 times her walking speed, so her driving speed is 15W km/h.

We can calculate the time taken for the driving portion by dividing the distance driven by the driving speed:

Time for driving = Distance driven / Driving speed

= 45 km / (15W km/h)

= 3/W hours

Similarly, we can calculate the time taken for the walking portion:

Time for walking = Distance walked / Walking speed

= 2 km / W km/h

= 2/W hours

According to the problem, the total time for the drive and walk is 1.5 hours. So we can set up the equation:

Time for driving + Time for walking = 1.5 hours

3/W + 2/W = 1.5

Multiplying both sides of the equation by W to eliminate the denominators, we get:

3 + 2 = 1.5W

5 = 1.5W

Dividing both sides by 1.5, we find:

W = 5/1.5

W ≈ 3.33 km/h

So Sofia's walking speed is approximately 3.33 km/h.

To find Sofia's driving speed, we can multiply her walking speed by 15:

Driving speed = 15W

= 15 * 3.33 km/h

≈ 49.95 km/h

Therefore, Sofia's driving speed is approximately 49.95 km/h.

User Ram Hemasri
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3 votes

Final answer:

Sofia's driving speed was calculated to be 50 kilometers per hour, based on her walking speed, the given distances traveled, and the total time taken for both walking and driving.

Step-by-step explanation:

The student asked about Sofia's speed while driving, given that she drove 45 kilometers, ran out of gas, walked 2 kilometers, and the whole journey took 1.5 hours. Additionally, it is known that her driving speed is 15 times her walking speed.

Let's denote the walking speed as w, and thus her driving speed will be 15w. The time taken to walk 2 kilometers is distance/speed, which is 2/w hours, and the time taken to drive 45 kilometers is distance/speed, which is 45/(15w) or 3/w hours. The total time spent walking and driving is 1.5 hours, so:

2/w + 3/w = 1.5

Solving the equation for w, we get:

5/w = 1.5

w = 5/1.5

w = 3.33 km/h (walking speed)

Sofia's driving speed is 15 times the walking speed:

Driving speed = 15 * 3.33 km/h = 50 km/h

Therefore, Sofia was driving at a speed of 50 kilometers per hour.

User Gisgyaan
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