RRB NTPC · Question 97
The upstream speed of the boat is 40 km/hr and the speed of the boat in still water is 55 km/hr. What is the downstream speed of the boat? A. 75 km/hr B. 70 km/hr C. 60 km/hr D. 65 km/hr
Show answer & explanation
Answer: (B) B
Explanation
Upstream speed = boat speed − stream speed, so 40 = 55 − s and the stream speed s = 15 km/h. Downstream speed = 55 + 15 = 70 km/h.