A man goes to a place on bicycle at speed of 16 km/hr and

A man goes to a place on bicycle at speed of 16 km/hr and comes back at lower speed. If the average speed is 6.4 km/hr in total journey, then the return speed (in km/hr) is :

Let the speed of cyclist while returning be x kmph.

∴ Average speed =	2 × 16 × x
	16 + x

⇒ 6.4 =	32x
	16 + x

⇒ 6.4 × 16 + 6.4x = 32x
⇒ 32x – 6.4x = 6.4 × 16
⇒ 25.6x = 6.4 × 16

⇒ x =	6.4 × 16
	25.6

= 4 kmph.