-
. Its rowing speed in still water is (in km/ hr).A man rows 750 m in 600 seconds against the stream and returns in
71 minutes 2
-
- 5.5
- 5.75
- 5
- 5.25
- 5.5
Correct Option: D
According to question ,
| Rate downstream = |  |  | m/minute | |
| 2 | ||||
Rate downstream = 100 m/minute
| Rate downstream = | kmph = 60kmph | |
| 1000 |
| Rate upstream = | | × | | kmph | ||
| 600 | 5 |
Rate upstream = 4.5 kmph
| ∴ Rowing speed in still water = | (6 + 4.5) = | = 5.25 kmph | ||
| 2 | 2 |
Second method to solve this question :
| Here, p = | |
| min | |
| 2 | |
| p = | = 6km/hr | |
| 1000 × 15 |
| q = | = | ||
| 600s | 1000 × 600 |
q = 4.5 km/hr
| ∴ Speed of Boat = | (p + q) | |
| 2 |
| Speed of Boat = | (6 + 4.5) = 5.25 km/hr | |
| 2 |
