## Precalculus (6th Edition) Blitzer

$\dfrac{60}{100}$
We see that there are a total of $100$ students in this survey and this can be our denominator. Also, there are $40$ students with brown eyes in this survey and this will be our numerator. This implies thatt here are $60$ students who do not have brown eyes. That is, $\dfrac{60}{100}$