Answer:
25
Explanation:
so lets write our ratios.
Students that wear glasses to the whole class:
2 : 5
Students that wear glasses to those that dont:
2 : 3
And now if there are 15 kids in the class that dont wear glasses, that means that we have to multiply the second ratio by 5 to get the amount of students that don't wear glasses to 15. So now the second ratio will be
10 : 15
10 being amount of kids with glasses, and 15 kids without glasses. Now we just have to add them to get the answer of 25.