## 189. Math Puzzle $2 / 81$

Marlies takes great pleasure in her houseplant. It grows by about five percent each month, compared to its height at the beginning of the month. Currently, its height is 60 centimeters.

By how many centimeters will the plant have grown in the next three months?
Marlies' plant continues to grow well.

1. Month: 5 percent means 1/20 of the initial value. $1 / 20$ of $60 \mathrm{~cm}$ is $3 \mathrm{~cm}$. At the end of the first month, the plant measures $63 \mathrm{~cm}$.
2. Month: $1 / 20$ of 63 is $3.15 \mathrm{~cm}$. At the end of the second month, the plant is $66.15 \mathrm{~cm}$ tall.
3. Month: $1 / 20$ of $66.15 \mathrm{~cm}$ is about $3.3 \mathrm{~cm}$.

Thus, after three months, the plant has grown to about 69.45 cm. This is an increase of about $9.45 \mathrm{~cm}$.