Al swims across an 80 m river. The current carried him 30 m downstream. How far did he swim?

1 answer

To determine the distance Al swam, we need to subtract the distance carried downstream by the current (30m) from the total distance across the river (80m).
Thus, Al swam a distance of 80m - 30m = <<80-30=50>>50m. Answer: \boxed{50}.