Which linear function has initial value 7?
y = 7x - 3
y = 3x + 7
y = - 3x - 7
y = 7x - 3

a) 22,500  b) 2250 seconds (or 37.5 minutes)

Step-by-step explanation:

a) There are 1000 ml in a liter.

Therefore, the rate of water flowing in can be 3000 ml per minute. To convert this into per second, we divide 3000 by 60.

This becomes 50 ml per second. If the tank fills in completely in 450 seconds,  we multiply 50 by 450 to get how much water in ml was used to fill the tank completely. 50 times 450 = 22,500. Therefore, the capacity of the tank is 22,500.

b) Since water keeps flowing into the tank at a rate of 50 ml per second, and water flows out at a rate of 60 ml per second, we can define the rate flowing out of the tank as 10 ml per second.

Because the maximum capacity of the tank is 22,500 ml, we divide this by 10 ml (the rate flowing out) to get how many seconds it will take for the tank to drain out completely. 22,500 divided by 10 is 2250.

So, it will take 2250 seconds for the tank to drain completely. In minutes, this becomes 37.5 minutes.