- A4 hours
- B5 hours
- C3 hours
- D2 hours
Step-by-Step Solution
Downstream speeds: A 25, B 20 km/h. B's lead = 20 km. Gap closes at 5 km/h ⇒ 20 ÷ 5 = 4 hours.
Answer: A) 4 hours
Launch B (15 km/h in still water) leaves a jetty going downstream. One hour later launch A (20 km/h in still water) leaves the same jetty, also downstream. The current is 5 km/h. How long after starting does A overtake B?
Competition practiceBoats & Streams
Master this topic in 30 minutes a day.
Don't just memorise the answer — build a daily practice habit.
Practice 5 Similar Questions Free →All Boats & Streams practice questions
More Boats & Streams practice
In the morning the river flows at 2 km/h; by evening it flows at 4 km/h. A boat (12 km/h…The current is one-fifth of a boat's speed in still water. A 36 km out-and-back trip (36…A boat's upstream speed is 25% less than its downstream speed. Over 30 km it needs 1…A boat's downstream and upstream speeds are in the ratio 7 : 3, and the current flows at…Rahul's shortcut: "A boat does 12 km/h in still water, so 30 km out and 30 km back takes…