1.  A farmer travelled a distance of 61 km in 9 hours. He travelled partly on foot @ 4 km/hr and partly on bicycle @ 9 km/hr. The distance travelled on foot is:
A. 14 km
B. 15 km
C. 16 km
D. 17 km

Answer: Option C

Explanation:

Let the distance travelled on foot be x km.

Then, distance travelled on bicycle = (61 -x) km.

So, x + (61 -x) = 9
4 9

9x + 4(61 -x) = 9 x 36

5x = 80

x = 16 km.