A Math test starts at 12:35 and lasts for $4 \frac{5}{6}$ hours. At what time does the test end?
First, let's observe that

$$
\frac{5}{6} \text{ h} = \frac{5}{6} \times 60 \text{ min} = 50 \text{ min}
$$

so the exam lasted $4 \text{ h} 50 \text{ min}$. Adding the hours and minutes, we get

$$
12 \text{ h} 35 \text{ min} + 4 \text{ h} 50 \text{ min} = 16 \text{ h} 85 \text{ min}
$$

But, $85 \text{ min} = 1 \text{ h} 25 \text{ min}$. Therefore, the exam ends at $16 \text{ h} 85 \text{ min} = 17 \text{ h} 25 \text{ min}$.