Answer: There are 96 students who attend Chess club on Wednesday.
Step-by-step explanation:
Since we have given that
Total number of students in challenger Middle school = 800
Percentage of students stay after school for chess club in Wednesday = 12%
So, Number of students who attend Chess club on Wednesday is given by
[tex]\frac{12}{100}\times 800\\\\=12\times 8\\\\=96[/tex]
Hence, there are 96 students who attend Chess club on Wednesday.