#### Answer

$\frac{4}{5}$

#### Work Step by Step

We can write the given ratio as a fraction and then simplify in lowest terms.
$\frac{12eggs}{15eggs}$
Since both the denominator and numerator have the same unit, we can divide out the common unit.
$\frac{12}{15}=\frac{12\div3}{15\div3}=\frac{4}{5}$