Total distance travelled by man = 99 km in 9 hours Let distance travelled on foot = $$d$$ km => Distance travelled on bicycle = $$(99-d)$$ km Speed on foot = 9 km/hr and on bicycle = 18 km/hr Using, time = distance/speed Total time taken = $$frac{d}{9}+frac{99-d}{18}=9$$ => $$frac{1}{9}(d+frac{99-d}{2})=9$$ => $$frac{2d+99-d}{2}=81$$ => $$d+99=81 imes 2=162$$ => $$d=162-99=63$$ km => Ans - (C)