Discussion
A man can row upstream at 25 kmph and downstream at 35 kmph, and then find the speed of the man in still water?
Answer: C
With \( b \) the still-water speed and \( r \) the stream's,
\[ \text{downstream} = b + r, \qquad \text{upstream} = b - r \]
\[ b = \frac{(b+r) + (b-r)}{2}, \qquad r = \frac{(b+r) - (b-r)}{2} \]
\[ b = \frac{35 + 25}{2} = 30 \text{ kmph} \]
The still-water speed is the average of the two, so it must lie between 25 and 35 - ruling out 60 and 10 on sight. The stream itself runs at \( \tfrac{35-25}{2} = 5 \) kmph.
No comment is present. Be the first to comment.
Loading…
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