Gautam goes office at a speed of 12 kmph and return homes at 10 kmph. His average speed is :

Answer: Option C

Average speed = $$\frac{2xy}{x+y}$$
x = 10 km/hr
y = 12 km/hr
Average speed = $$\frac{2\times 10\times 12}{\left(10+12\right)}$$
∴ Average speed = 10.9 km/hr