To find the fraction of students who are boys, we first need to determine how many boys there are in the school.
- We know the total enrollment is 600 students.
- There are 330 girls.
Now, we can calculate the number of boys:
\[ \text{Number of boys} = \text{Total students} - \text{Number of girls} = 600 - 330 = 270 \]
Next, we express the fraction of boys in terms of the total enrollment:
\[ \text{Fraction of boys} = \frac{\text{Number of boys}}{\text{Total enrollment}} = \frac{270}{600} \]
Now we simplify the fraction \(\frac{270}{600}\):
To simplify, we can find the greatest common divisor (GCD) of 270 and 600. Both numbers can be divided by 30:
\[ \frac{270 \div 30}{600 \div 30} = \frac{9}{20} \]
Thus, the fraction of students who are boys in simplest terms is:
\[ \frac{9}{20} \]
So the answer is \(\frac{9}{20}\).