Answer:
17%
Step-by-step explanation:
If 30% of the school is girls and 10% wear glasses, that means that at least 3% of the school wears glasses. (10 percent of 30%) If 70% of the school is boys and 20% of boys wear glasses, at least 14% of the school wears glasses. (20% of 70%) If you add both of those numbers together it adds up to 17%.