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If a boat goes 100 km downstream in 10 hours and 75 km upstream in 15 hours, then the speed of the stream is
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- 2 km/hour
- 2·5 km/hour
- 3 km/hour
- 3·5 km/hour
- 2 km/hour
Correct Option: B
As per the given in question ,
Rate downstream = | = 10 kmph | |
10 |
Rate upstream = | = 5 kmph | |
15 |
∴ Speed of current = | ||
2 |
Speed of current = | (10 - 5) = 2.5 kmph | |
2 |
Aliter : Using Rule 1,
Here, p = | = 10 kmph | |
10 |
q = | = 5 kmph | |
15 |
Speed of Stream = | ![]() | ![]() | = | ![]() | ![]() | = 2.5 km/hr | ||
2 | 2 |