Discussion
What will be Raj’s speed in still water as well as speed of the river, if he can go downstream at 18 km/hr and upstream at 10 km/hr?
Answer: B
Write \( b \) for the boat's speed in still water and \( r \) for the stream's. Then
\[ \text{downstream} = b + r, \qquad \text{upstream} = b - r \]
\[ b = \frac{18 + 10}{2} = 14 \text{ km/h} \]
\[ r = \frac{18 - 10}{2} = 4 \text{ km/h} \]
Checking: \( 14 + 4 = 18 \) downstream and \( 14 - 4 = 10 \) upstream. The 28 and 8 option forgets to halve; the still-water speed must always lie between the two given speeds.
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