Answer:
7 minutes
Step-by-step explanation:
The scientist changes the temperature for the solution at a rate of -7°C per minute. We need to find out how long it'll take for the solution's temperature to change from 0°C to -49°C. So, we divide -7 by -49 to find out how long it will take:
-49 / -7 = 7
It will take 7 minutes for the temperature to reach -49°C.
