Answer: After 5 minutes, the sensor will read 300 liters.
After -7 minutes, the sensor sensor should have read 120 liters.
Step-by-step explanation:
Given: Due to a problem, the sensor does not start working until some time into the filling process.
The initial amount of water detected by sensor = 225 litres
Since, the hose fills the aquarium at a constant rate of 15 liters per minute.
Let x be the time , and y be reading of sensor then
[tex]y=225+15x[/tex]
Therefore, the sensor reads after 5 minutes, substitute x=5 in the above equation, we get
[tex]y=225+15(5)=300\ liters[/tex]
To find the sensor reading at time -7 minutes substitute x=-7 in the above equation, we get
[tex]y=225+15(-7)=120\ liters[/tex]
Therefore, the sensor should have read 120 liters at time -7 minutes.