Influenza

In the first week of February, 5% of the children in a kindergarten were ill with influenza. In the second week, nine more children fell ill, bringing the percentage of ill children up to 20%. How many children attend the kindergarten?

Final Answer:

n =  60

Step-by-step explanation:

$$\begin{gathered} q_1=5\%=\frac{5}{100}=\frac{1}{20}=0.05 \\ {q}_2=20\%=\frac{20}{100}=\frac{1}{5}=0.2 \\ {q}_1\cdot n+9=q_2\cdot n \\ 0.05\cdot n+9=0.2\cdot n \\ 0.15n=9 \\ n=\frac{9}{0.15}=60 \\ n=60 \end{gathered}$$

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