The duck flying from the river to the lake flew for 4 minutes at a speed of 800 m / min. Then it flew 3 times more

The duck flying from the river to the lake flew for 4 minutes at a speed of 800 m / min. Then it flew 3 times more than it had already eaten. How many meters separates the river from the lake?

1) Let’s find out what distance the duck covered in the first 4 minutes of flight, if we know that during this period it flew at a speed of 800 m / min.
800 * 4 = 3200 meters.
2) Let us find out what path the duck covered in the rest of the way, if we know that it has flown 3 times more than in the first 4 minutes of the flight.
3200 * 3 = 9600 meters.
3) Let’s find out what is the distance from the river to the lake, if we learned that the duck flew 3200 m and 9600 m.
3200 + 9600 = 12800 meters.
12800 m = 12 km 800 m.
Answer: the distance from the river to the lake was 12 km 800 meters.