A farmer travelled a distance of 61 km in 9 hours. He travelled

A farmer travelled a distance of 61 km in 9 hours. He travelled partly on foot at a speed of 4 km/hour and partly on bicycle at a speed of 9 km/hour. The distance travelled on foot is :

Length of journey on foot = x km. (let).
∴ Length of journey on cycle = (61 – x ) km.
According to the question,

Time =	Distance
	Speed

∴	x	+	61 − x	= 9
	4		9

⇒	9x + 244 − 4x	= 9
	36

⇒ 5x + 244 = 36 × 9 = 324
⇒ 5x = 324 – 244 = 80

⇒ x =	80	= 16 km
	5