### Instruction: A world-record swimmer and a dolphin compete in a 400-meter race. The swimmer swims at a rate of 2 meters per second, and the dolphin swims at a rate of 8 meters per second. When the dolphin crosses the finish line, how many meters is the swimmer from the finish line?### Response: I need to find the distance between the swimmer and the finish line when the dolphin finishes the race.
To do that, I need to know how long it takes for the dolphin to finish the race, and how far the swimmer has traveled in that time.
The dolphin's time is the distance divided by the rate, so it takes the dolphin 400 / 8 = 50 seconds to finish the race.
The swimmer's distance is the rate times the time, so the swimmer has traveled 2 * 50 = 100 meters in 50 seconds.