Answer
$\frac{1}{12}$
Work Step by Step
We can write the given ratio as a fraction and then simplify in lowest terms.
We know that there are 60 minutes in 1 hours, so we can write 3 hours as $(3\times60)=180$ minutes.
$\frac{15minutes}{180minutes}$
Since both the denominator and numerator have the same unit, we can divide out the common unit.
$\frac{15}{180}=\frac{15\div15}{180\div15}=\frac{1}{12}$
