A person goes to his office at 1/3rd of the speed at which he returns from his office. If the avg speed during the whole trip is 27m/h. what is the speedof the person while he was going to his office? Select:
A) 8km/h	B) 10km/h	C) 12km/h	D) 13km/h	E) 18km/h
u = k , v= 3k   \inline \therefore \frac{2uv}{u+v}\: \: \Rightarrow \frac{2\times k\times 3k}{(k+3k)}=27   \inline \Rightarrow 1.5k = 27   \inline \Rightarrow k=18km/h   18km/h
<result>E</result>
A person goes to his office at 1/3rd of the speed at which he returns from his office. If the avg speed during the whole trip is 27m/h. what is the speedof the person while he was going to his office?