We have 21 glasses that are used in the “speed stack” game that consists of stacking pyramid-shaped glasses as quickly as possible.

The dimensions of the vessels used are 10cm high, 6cm wide at the top and 5cm at the bottom. The glasses have a shape such that if we introduce one inside the other the total height of the set is 11cm since each glass has a stop inside that does not allow them to fit completely.

With the glasses we have we want to reach as high as possible.

**Can you think of the best way to stack them and how high can we get?**

#### Solution

The best way to stack the glasses to maximize the height is to do it one on top of the other, inverting the glass in each level so that they can be stacked so that we always take advantage of the total height of the glass. If we have 21 glasses 10cm high each, we can reach a height of 2 meters and 10cm.