ANSWER:
3,400
STEP BY STEP:
If 2/17 were socialists, then 15/17 were not socialists.
So...
3000 = 15/17x
(x represents the total number of teachers)
Multiply by 17 on both sides.
51,000 = 15x
Divide by 15 on both sides.
3,400 = x
Total number of teachers: 3,400.