A) \[384\text{ }km/h\]
B) \[370\text{ }km/h\]
C) \[368\text{ }km/h\]
D) None of these
Correct Answer: A
Solution :
Let each side of the square be x km and let the average speed of the plane around the field be y km/h. Then, \[\frac{x}{200}+\frac{x}{400}+\frac{x}{600}+\frac{x}{800}=\frac{4x}{y}\] \[\Rightarrow \] \[\frac{25x}{2400}=\frac{4x}{y}\] \[\Rightarrow \] \[y=\left( \frac{2400\times 4}{25} \right)=384.\] \[\therefore \] Average speed \[=384\text{ }km/h.\]You need to login to perform this action.
You will be redirected in
3 sec