Answer:
200 students must agree to attend in order for the school to have the festival.
Step-by-step explanation:
200 is 40% of 500. We can also use fractions to figure this out.
For 100 to become 500 it must be multiplied by 5. And whatever we do to the denominator we have to do to the numerator. So we multiply 40 × 5 = <em>x</em>
<em>x</em> = 200