A) 45kmh \[{{\text{h}}^{-\text{1}}}\]
B) 90kmh \[{{\text{h}}^{-\text{1}}}\]
C) 60kmh \[{{\text{h}}^{-\text{1}}}\]
D) None of these
Correct Answer: B
Solution :
Let speed of the train in later half \[=x\], then the time taken to travel later \[40km=40/x\]hours Total time taken\[=40/30+40/x\] Average speed\[=\frac{80}{4/3+40x}=45\] Solve the equation to find value of xYou need to login to perform this action.
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