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 the rate 4 kmph and partly on bicycle at the rate 9 kmph. The distance travelled on foot is

Distance travelled by farmer on foot = x km (let)
∴ Distance covered by cycling = (61–x ) km.

Time =	Distance
	Speed

According to the question,

x	+	61 − x	= 9
4		9

⇒	9x + 61 × 4 − 4x	= 9
	9 × 4

⇒ 5x + 244 = 9 × 9 × 4 = 324
⇒ 5x = 324 – 244 = 80

⇒ x =	80	= 16 km.
	5

Second Method :
Here, t = 9, x= 61
u = 4, v = 9

Time taken =		vt − x
		v − u

=	9 × 9 − 61
	9 − 4

=	20	= 4 hrs.
	5

Distance travelled
= 4 × 4 = 16 km