- A20 minutes
- B15 minutes
- C30 minutes
- D0 minutes
Step-by-Step Solution
Actual = 30/15 + 30/9 = 2 + 3⅓ = 5⅓ h = 5 h 20 min. The current slows the round trip, so Rahul is 20 minutes short.
Answer: A) 20 minutes
Rahul's shortcut: "A boat does 12 km/h in still water, so 30 km out and 30 km back takes 60 ÷ 12 = 5 hours." The river flows at 3 km/h. By how many minutes is his answer short?
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