A) \[30\text{ }km/hr\]
B) \[50\text{ }km/hr\]
C) \[\text{48 }km/hr\]
D) \[\text{60 }km/hr\]
Correct Answer: C
Solution :
Let the points A, B, C and D be separated by 1 km. Then \[{{t}_{AB}}=\frac{1}{60}hr,{{t}_{BC}}=\frac{1}{40}hr\] \[\therefore \,\,\,<{{v}_{AC}}>=\frac{1+1}{\frac{1}{60}+\frac{1}{40}}=48\,km/hr\Rightarrow {{t}_{CD}}\frac{1}{48}hr\] \[Now\,\,<{{v}_{AD}}>=\frac{1+1+1}{\frac{1}{60}+\frac{1}{40}+\frac{1}{48}}=48\,km/hr\]
You need to login to perform this action.
You will be redirected in
3 sec
