First you need to calculate how many student is good at math, and that is by knowing how many student forms the 72% of the class total number.
This is by multiplying the total number of the students by the percentage that are good at math.
[tex]25* \frac{72}{100} =18[/tex]
So 18 students are good at math.
So the rest, which are not good at math, are equal to;
[tex]25-18=7[/tex]
The answer is 7.
Hope this helps!
