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

Options

A. 17km
B. 16km
C. 15km
D. 14km

Answer

B

Explanation

मानाकि उसने x घंटे तक पैदल सफर किया।
` therefore 4 xx x + 9 (9-x) = 61`
` rArr 4x + 81 - 9x = 61`
` rArr 5x = 81 - 61` ` rArr x = 20/5 = 4hr. `
अतः उसके द्वारा पैदल चली गई दूरी = 4 x 4 = 16 km.