- A2 h 15 min
- B2 h
- C2 h 30 min
- D1 h 40 min
Step-by-Step Solution
First 10 km at 12 − 2 = 10 km/h: 1 h. Next 10 km at 12 − 4 = 8 km/h: 1 h 15 min. Total = 2 h 15 min.
Answer: A) 2 h 15 min
A launch (12 km/h in still water) heads 10 km upstream on a 2 km/h current. Then the current doubles, and it continues 10 km further upstream. What is the total time for the 20 km?
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