WBCS.LIVE practice question

The speed of a boat in perfectly still water is 10 km/hr. If the speed of the river stream is 2 km/hr, what is the boat's upstream speed?

Solve this multiple-choice question and check the correct answer with its explanation below.

Answer options

  1. 12 km/hr
  2. 8 km/hr
  3. 10 km/hr
  4. 6 km/hr

Correct answer and explanation

Correct answer: 8 km/hr

Explanation: āœ… Correct Answer: B) 8 km/hr šŸ“š Explanation: When a boat travels upstream, it physically moves directly against the flow of the water current. Therefore, the effective upstream speed is calculated by simply subtracting the speed of the stream from the speed of the boat in still water. Subtracting 2 km/hr from 10 km/hr directly gives an effective upstream speed of exactly 8 km/hr.