Question

A motor-boat, travelling at the same speed, can cover 25 km upstream and 39 km downstream in 8 hours. At the same speed, it can travel 35 km upstream and 52 km downstream in 11 hours. The speed of the stream is

• A. 2 km/hr
• B. 3 km/hr
• C. 4 km/hr
• D. 5 km/hr

Answer 1

Answer:

C. 4 km/hr

25 up+39 down = 8 hours. 35 up +52 down = 11 hours Solving 13 down-stream in 1 hours and 5 up-stream in 1 hour. Speed of stream 13-5/ 2 = 4km/hr