#### Explanation:

Using the formula $S I = \frac{P \times R \times T}{100}$, where $S I$ is Simple Interest, $P$ is the Principal Amount, $R$ is the Rate of Interest, and $T$ is the time period in number of years, we can calculate:

$S I = \frac{55 \times 4 \times 5}{100}$

$S I = \frac{55 \times 20}{100}$

$S I = \frac{55 \times \cancel{20}}{\cancel{100} 5}$

$S I = \frac{55}{5}$

$S I = 11$