You start with 600 liters and are adding 34 liters per minute .
You need to multiply 34 by the number of minutes ( T) and then add that total to the 600 to find the total amount of water (W)
The equation would be W = 34T + 600
Now replace T with 13 minutes and solve for W:
W = 34(13) + 600
W = 442 + 600
W = 1,042 total liters.