The information given is that there are 12 boys and 16 girls in the classroom. The question is not about the ratio of girls to boys but about the ratio of girls to STUDENTS. You need to add the amount of girls plus the amount of boys to get the total amount of students.
The answer is A "For every half an hour there is 1/5 of the bucket is filled" Hope I helped B: Not sure not very good at equations :( C: Well there is Half an hour so if you multiply that by 5 then its. 2 1/2 hours :) Hope I helped
