This section caters exclusively to word problems involving **combined variation**. As introduced in the previous section, *combined variation* is when there is both a direct (multiplication) and inverse (division) variation that occurs together. Be sure to watch all three parts as they examine different scenarios commonly found in textbooks, all of which you’re expected to know.

- Watch Part 2 (emptying time of a cylinder; kinetic energy)
- Watch Part 3 (volume, temperature, and pressure)