Discussion
A school boy walks from his house to school at the rate of 4 kmph. He reaches the school 20 minutes earlier than the schedule time. If he walks at the rate of 3 kmph, he reaches the school 20 minutes late. What is the distance of the school from his house?
Answer: D
The distance is 8 km.
The two journeys differ in time by 20 + 20 = 40 minutes, that is \(\frac{2}{3}\) hour:
\[ \begin{aligned} \frac{d}{3} - \frac{d}{4} &= \frac{2}{3} \\ \frac{d}{12} &= \frac{2}{3} \Rightarrow d = 8\ \text{km} \end{aligned} \]
Check: 8 km takes 2 hours at 4 km/h and 2 h 40 min at 3 km/h, so the scheduled time is 2 h 20 min, early by 20 minutes and late by 20 minutes as stated. 480 km comes from working in minutes without converting.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development