A farmer travelled a distance of 61 km in 9 hours. He travelled partly on foot at 4 km/hr and partly on bicycle at 9 km/hr. The distance travelled on foot is :	Choices:
A) 1 hr 16 min  B) 1 hr 17 min  C) 1 hr 18 min  D) 1 hr 19 min  E) None
Sol.   Let the distance travelled on foot be x km.   then, distance travelled on bicycle = (61 - x) km.   So, x/4 + (61-x)/9 = 9   ⇔ 9x + 4 (61 - x) = 9 * 36   ⇔ 5x = 80   ⇔ x = 16 km.   1 hr 16 minnswer 1 hr 16 min
<result>A</result>
A farmer travelled a distance of 61 km in 9 hours. He travelled partly on foot at 4 km/hr and partly on bicycle at 9 km/hr. The distance travelled on foot is :