A) 90 sec
B) 9 sec
C) 54 sec
D) 60 sec
Correct Answer: B
Solution :
Required time \[=\frac{\text{total}\,\,\text{distance}}{\text{Relative}\,\,\text{speed}}\] Relative speed =49+5 = 54 km/hr. \[=54\times \frac{5}{18}m/\sec \] = 15 m/sec Hence, Required time\[=\frac{135}{15}\] \[=9\sec \]You need to login to perform this action.
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