Answer:
15
Step-by-step explanation:
The total number of teachers in the school is 100.
The number who teach Science is 60
The who teach humanities is 25.
The number that teach both humanities and Science is 15.
We want to find the number who teach Science but not Humanities.
We obtain this by subtracting the number of teachers who teach both subjects from the number that teach Science.
Therefore 25 teaches science but not Humanities