Subject: General Aptitude · Chapter: Time and Distance · Exam: · Marks: · Difficulty:
$A$ walks at 4 kmph and 4 hours after his start, $B$ cycles after him at 10 kmph. How far from the start does $B$ catch up with $A$ ?
(a)16.7 km
(b)18.6 km
(c)21.5 km
(d)26.7 km
Answer
Answer (as printed): D
Explanation
Suppose after $x \mathrm{km}$ from the start $B$ catches up with $A$. Then, the difference in the time taken by $A$ to cover $x \mathrm{km}$ and that taken by $B$ to cover $x \mathrm{km}$ is 4 hours. $$\therefore \frac{x}{4}-\frac{x}{10}=4 \text { or } x=26.7 \mathrm{km} .$$