2016 · Q26
A person can row downstream 20 km in 2 hours and upstream 4 km in 2 hours. What is the speed of the current ?
Elementary MathematicsTime, Speed and Distance
- A2 km/hour
- B2.5 km/hour
- C3 km/hour
- D4 km/hour
Explanation
Downstream speed = 20/2 = 10 km/h and upstream speed = 4/2 = 2 km/h. The current's speed is half the difference: (10−2)/2 = 4 km/h (option D).