At the start of an experiment, the temperature of a solution was -12°c. during the expirament

The final temperature of the solution was 5°C

Step-by-step explanation:

we know that

1) At the start of an experiment, the temperature of a solution was -12°C

In this moment the temperature is -12°C

2) During the experiment, the temperature of the solution rose 5°C each hour during 4 hours

so

5°C*4=20°C

In this moment the temperature is -12°C+20°C=8°C

3) The temperature changed by -3°C

In this moment the temperature is 8°C-3°C=5°C

the answer is 99.