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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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Question

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?

Sum
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Solution

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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Chapter 10: Direct and Inverse Proportions - Exercise [Page 323]

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NCERT Exemplar Mathematics Exemplar [English] Class 8
Chapter 10 Direct and Inverse Proportions
Exercise | Q 70. | Page 323

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