First of all, when you type a question, please make sure you type it correctly. You were missing some important information in this problem. Here's the correct problem:

Of all the students in a certain dormitory, half are first-year students and the rest are second-year students. If 4/5 of the first-year students have not declared a major and if the fraction of second-year students who have declared a major is 3 times the fraction of first-year students who have declared a major, what fraction of all the students in the dormitory are second-year students who have not declared a major?

Let's assume that there are x students in a certain dormitory.

x/2 are first year students.

x-x/2= x/2 are second year students.

4/5*(x/2)=2x/5 have not declared a major

1/5*x/2=x/10 have declared a major

3*x/10=3x/10 are the amount of second year students who have declared a major.

x/2-3x/10=x/5 are the amount of second year students who have not declared a major.

B is your answer.

truplayer256 wrote:First of all, when you type a question, please make sure you type it correctly. You were missing some important information in this problem. Here's the correct problem:

Of all the students in a certain dormitory, half are first-year students and the rest are second-year students. If 4/5 of the first-year students have not declared a major and if the fraction of second-year students who have declared a major is 3 times the fraction of first-year students who have declared a major, what fraction of all the students in the dormitory are second-year students who have not declared a major?

Let's assume that there are x students in a certain dormitory.

x/2 are first year students.

x-x/2= x/2 are second year students.

4/5*(x/2)=2x/5 have not declared a major

1/5*x/2=x/10 have declared a major

3*x/10=3x/10 are the amount of second year students who have declared a major.

x/2-3x/10=x/5 are the amount of second year students who have not declared a major.

B is your answer.

Thanks for the explanation.