Speed of motorboat in still water is 35 kmph. If the motorboat travels 100 km…
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Speed of motorboat in still water is 35 kmph. If the motorboat travels 100 km along the stream in 2 hour 30 min, then the time taken by it to cover the same distance against the stream is :
- A.
3 hr 20 min
- B.
4 hr 5 min
- C.
12 hr
- D.
8 hr
Attempted by 4 students.
Show answer & explanation
Correct answer: A
Solution: The speed of the motorboat in still water is 35 km/hr.
let the speed of the stream = x km/hr
Downstream speed = Distance/time
= 100 / 2.5
= 40 km/hr
Speed of stream = 35 + x = 40
x = 5 km/hr
Upstream speed = 35 – 5 = 30 km/hr
Time taken in upstream = 100/30 = 3 hour 20 min