Question

A fish can travel 30km/h in still water. How long will it take to arrive 12km downstream in a river flowing 6km/h?

Answer 1

30 + 6 = 36

36/12 = 3



So, it would take it 3 hours to go 12 kms downstream.



Note that we added 30 and 6 because it was going downstream. If it was going upstream, then we would have had to subtract.