Arun had ridden one-third the total distance of his trip when his scooter got punctured. He finished the… · ABC26GN3759
Subject: General Aptitude · Chapter: Time and Distance
Arun had ridden one-third the total distance of his trip when his scooter got punctured. He finished the journey on foot, spending twenty times as long walking as he had spent riding. What was the ratio of his riding speed to his walking speed?
(a)4 : 1
(b)5 : 1
(c)10 : 1
(d)20 : 1
Answer
Answer (as printed): C
Explanation
Let the total distance be $x \mathrm{km}$ and time spent in riding be $y$ hours. Then, distance covered by riding $=\left(\frac{x}{3}\right) \mathrm{km}$. Distance covered by walking $=\left(x-\frac{x}{3}\right) \mathrm{km}=\frac{2 x}{3} \mathrm{km}$. Time spent in walking = (20 y) hrs. Riding speed $=\left(\frac{\frac{x}{3}}{y}\right) \mathrm{km} / \mathrm{hr}=\left(\frac{x}{3 y}\right) \mathrm{km} / \mathrm{hr}$. Walking speed $=\frac{\left(\frac{2 x}{3}\right)}{20 y} \mathrm{km} / \mathrm{hr}=\left(\frac{x}{30 y}\right) \mathrm{km} / \mathrm{hr}$. ∴ Required ratio $=\frac{x}{3 y}: \frac{x}{30 y}=1: \frac{1}{10}=10: 1$.