Percentage 16173

In 5A class today, there were four pupils, and in 5B, there were two pupils. What percentage of Fridays was in school if 21 pupils attend 5A and 5B is six pupils more?

Correct answer:

p =  87.5 %

Step-by-step explanation:

$$\begin{gathered} a=21 \\ b=21+6=27 \\ x=(a-4)+(b-2)=(21-4)+(27-2)=42 \\ y=a+b=21+27=48 \\ p=100\cdot \frac{x}{y}=100\cdot \frac{42}{48}=\frac{100\cdot 42}{48}=\frac{4200}{48}=\frac{175}{2}\%=87.5\% \end{gathered}$$

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