Gautam goes to office at a speed of 12 kmph and returns

Gautam goes to office at a speed of 12 kmph and returns home at 10 kmph. His average speed is :

Here distances are same.

∴ Average speed =		2xy		kmph
		x + y

=		2 × 12 × 10		kmph
		12 + 10

=		240		kmph
		22

= 10.9 kmph