The ratio of girls to boys in the school is given as 5:6. This means that for every 5 girls, there are 6 boys.
Given that there are 20 girls in the fifth grade, we can set up a proportion based on the ratio:
5 girls corresponds to 6 boys.
To find how many boys correspond to 20 girls, we can set up the following proportion:
\[ \frac{5 \text{ girls}}{6 \text{ boys}} = \frac{20 \text{ girls}}{x \text{ boys}} \]
Cross-multiplying gives us:
\[ 5x = 6 \times 20 \]
Calculating the right side:
\[ 5x = 120 \]
Now, divide both sides by 5 to find \(x\):
\[ x = \frac{120}{5} = 24 \]
Thus, there are 24 boys in the fifth grade.
The answer is 24 boys.