Question 21
A boat takes $2$ hours to travel downstream from $A$ to $B$, and $4$ hours to travel upstream from $B$ back to $A$. How many hours would a patch of floating water plants take to drift from $A$ to $B$?
Model clarification: the river current is constant, the boat keeps the same speed relative to the water, and both trips cover the same route distance. Floating plants move with the current.
Model clarification: the river current is constant, the boat keeps the same speed relative to the water, and both trips cover the same route distance. Floating plants move with the current.