The ratio of upstream to downstream speed of a boat is 3 : 5 and the…
2022
The ratio of upstream to downstream speed of a boat is 3 : 5 and the approximate time to cover 60 km 3 meters downstream and 60 km 2 meters upstream is 16 hours 10 minutes. Find time (approx.) taken by boat to cover 37 km in upstream?
- A.
4 hours
- B.
8 hours
- C.
6 hours
- D.
12 hours
- E.
10 hours
Attempted by 4 students.
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Correct answer: C
Let upstream speed = 3x and downstream speed = 5x. The distances are approximately 60 km each, and total time is 16 hours 10 minutes, about 16.17 hours. So 60/(5x) + 60/(3x) = 16.17, giving x about 1.98. Upstream speed is about 5.94 km/h. Time for 37 km upstream is 37/5.94, approximately 6 hours.