brandon is on one side of a river that is 70 m70 m wide and wants to reach a point 300 m300 m downstream on the opposite side as quickly as possible by swimming diagonally across the river and then running the rest of the way. find the minimum amount of time if brandon can swim at 2 m/s2 m/s and run at 4 m/s.at 4 m/s. (use decimal notation. give your answer to two decimal places.) the minimum amount of time is s