Algebra practice question

Answer: 3

Downstream speed is 18 km/h and upstream is 12 km/h. The current is half the 6 km/h gap: 3 km/h.

Common wrong answers

If you answered 6

6 is the difference between downstream and upstream speeds; the current is half of it.

If you answered 15

15 km/h is the boat's own speed in still water; the current is 3 km/h.

If you answered 18

18 km/h is the downstream speed, boat plus current.

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