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प्रश्न
A car covers a distance in 40 minutes with an average speed of 60 km/h. What should be the average speed to cover the same distance in 25 minutes?
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उत्तर
A car covers a distance in 40 min with an average speed = 60 km/h
= `(60 xx 1000)/60` m/min
In 1 min, the same distance can be cover with speed = `(60 xx 1000 xx 40)/60`
= 40000 m/min
In 25 min, the same distance can be cover with speed = `40000/25`
= 1600 m/min
= `1600/1000 xx 60` ...`[∵ 1m = 1/1000 km and 1 min = 1/60 h]`
= 16 × 6
= 96 km/h
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