Answer: 42%
Step-by-step explanation:
First step is to add all the known values ( 21, 25, 12). You get 58. Considering it is out of 100, all the known values are 58%
Next: Subtract 58 from 100. You get 42
Again, since it is out of 100, it is 42%
The answer is 42%
Hope this helped :D
