Boats & Streams · Question 30 · Hard
Boats & Streams question 30
A boat's speed in still water is 20 km/h. It takes 30 minutes longer to travel 24 km upstream than to travel 24 km downstream. What is the speed of the stream?
- 6 km/h
- 4 km/h
- 2 km/h
- 5 km/h
Answer and explanation
Answer: B. 4 km/h
Explanation: 24/(20 − s) − 24/(20 + s) = 1/2 gives s² + 96s − 400 = 0, so s = 4 km/h. Check: 24/16 − 24/24 = 1.5 − 1 = 0.5 hour.
Previous: A motorboat leaves a pier going downstream; at the same moment a log starts…
Practise boats & streams
Try a fresh set of boats & streams questions with an explanation after every answer, free and without signing up: Boats & Streams practice. Or sit a full placement mock test.
More boats & streams questions
- A boat takes 2 hours to cover a certain distance downstream and 3 hours to…
- A boat goes downstream from A to B and then comes back upstream to C, which is…
- A motorboat leaves a pier going downstream; at the same moment a log starts…
More quantitative aptitude practice
Permutation & Combination · Probability · Data Interpretation · Mensuration · Algebra & Equations · Number System · HCF & LCM · Simplification
LogicWiz Exams home · All practice topics · Placement mock tests · Daily 10 challenge