A) 15 min
B) 25 min
C) 50 min
D) \[1\frac{1}{2}\,\text{h}\]
Correct Answer: C
Solution :
Time taken to cover 20 km at the speed of 5 km/h = 4 h \[\therefore \] Fixed time\[=4\,h-40\,\,\min \] \[=3\,h\,\,20\min \] Time taken to cover 20 km at the speed of 8 km/h \[=\frac{20}{8}=2\,h\,30\,\,\min \] \[\therefore \] Required time \[=3\,h\,\,20\,\text{min}-2\,h\,\,30\,\text{min}=50\,\text{min}\]You need to login to perform this action.
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