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secondary 4 | E Maths
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Pls help
Date Posted: 4 years ago
Views: 209
You can't simply average the two values.
Let the distance for the whole journey be 2x km.
For the first 50% of the journey, or x km,
Time taken = x/20 h
For the remaining 50% of the journey, or x km,
Time taken = x/25 h
Total time taken
= x/20 + x/25
= 0.05x + 0.04x
= 0.09x
Average speed
= 2x/0.09x
= 200/9 km/h
= 22.22222222... km/h
~ 22.2 km/h
Let the distance for the whole journey be 2x km.
For the first 50% of the journey, or x km,
Time taken = x/20 h
For the remaining 50% of the journey, or x km,
Time taken = x/25 h
Total time taken
= x/20 + x/25
= 0.05x + 0.04x
= 0.09x
Average speed
= 2x/0.09x
= 200/9 km/h
= 22.22222222... km/h
~ 22.2 km/h
See 1 Answer
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Hope this helps!!
Date Posted:
4 years ago
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