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Question
A car takes 2 hours to reach a destination by travelling at the speed of 60 km/h. How long will it take when the car travels at the speed of 80 km/h?
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Solution
Let the time taken by the car to reach the destination, while travelling with a speed of 80 km/hr, be x hours.
The following table is obtained:
| Speed (in km/hr) | 60 | 80 |
| Time taken (in hours) | 2 | x |
Hence, the speed of the car and the time taken by the car are inversely proportional to each other. Therefore,
∴ 80 × x = 60 × 2
⇒ `x = (60 × 2)/80`
⇒ `x = 3/2 = 1 1/2`
The time required by the car to reach the given destination is `1 1/2` hours.
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