A) 59.5km/h
B) 80 km/h
C) 56.87 km/h
D) 57.1 km/h
Correct Answer: A
Solution :
Average speed \[=\frac{Total\text{ }Distance\text{ }Covered}{Total\text{ }Time\text{ }Taken}\] Total distance covered \[=(2\times 40)+\] \[\left( \frac{9}{2}\times 60 \right)+\left( \frac{7}{2}\times 70 \right)\] km \[=(80+270+245)\] km \[=595\] km Total time taken \[=2+\frac{9}{2}+\frac{7}{2}\] \[=\frac{4+9+7}{2}=\frac{20}{2}=10\] hours \[\therefore \] Average speed \[=\frac{595}{10}\] = 59.5 km per hourYou need to login to perform this action.
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