A beaver can swim 2 miles in 3 Hrs with a river current (downstream) ; the same beaver can swim 1 mile in 3 Hrs against the river current (upstream). What is the speed of the river current and how fast can the beaver swim in a calm lake (without current)?
TJ Prep Problems
TJ Prep practice problems for our students and readers. The problems provide a very small sampling of what Optimal TJ Prep students work with.