Question

A car takes 7hours to cover a certain distance at the speed of 48 kilometre /h . if the speed is decreased by 20 km / h , how much time will it take to cover the same distance​

Answer 1

Let :

• Distance traveled = x km

Given :

• When speed is 48 km/h time taken = 7hrs

To find :

Time taken to cover same distance when speed is decreased by 20 km/h

FORMULA used :

Distance = speed × time

SOLUTION :

• Distance = x km
• speed = 48 km/h
• time = 7h

Using distance = speed × time

➝ x = 48 × 7

➝ x = 336 km

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Now , speed is decreased by 20 km/h

➝ new speed = old speed - (decrease in speed) ➝ New speed = 48 km/h - 20km/h

➝ New Speed = 28 km/h

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• Distance = 336 km
• New Speed = 28 km/h
• Time = t

Using, distance = speed × time

➝ 336 km = 28km/h × t

➝ t = 336 km ÷ 28 km/h

➝ t = 12 hour

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ANSWER : 12 hours