buffdaddy wrote:

mbawaters wrote:

E?

I understand the OA is A but What if we have other students enrolled in subjects other than art & music?

What from the question telling is that there are only these two subjects?

Hi MBAWaters,

the students enrolled in the other subjects will simply go in the "not enrolled in either music or art" category

one simple way to solve these type of questions is using a 2d matrix (my preferred method).

let me know if you want me to explain this method

-buff

hi All,

a couple of people have asked me how this is solved with a 2d matrix.

below is how i normally do these type of questions

Of the students in a certain school, 15 percent are enrolled in an art class and 10 percent are enrolled in a music class. What percent of the students in the school are enrolled in neither an art class nor a music class?

the matrix looks like

\(\begin

\begin{tabular}{|l|l|l|l|}\hline

& Art & not Art & total \\ \hline

Music & & &10%\\ \hline

not Music & &x \\ \hline

total &15% & &100% \\ \hline

\end{tabular}\)

for the statements:

(1) 2/3 of the students who are enrolled in an art class are also enrolled in a music class.

\(\begin

\begin{tabular}{|l|l|l|l|}\hline

& Art & not Art & total \\ \hline

Music &\frac{2}{3} * 15 = 10%& 0 &10%\\ \hline

not Music & &x = 100-15 = 85% \\ \hline

total &15% & 100-15 = 85% &100% \\ \hline

\end{tabular}\)

from the above it can be deduced that x = 85%

(2) There are more than 100 students in the school.

\(\begin

\begin{tabular}{|l|l|l|l|}\hline

& Art & no Art & total \\ \hline

Music & & &10%\\ \hline

not Music & &x \\ \hline

total &15% & &100% > 100 students \\ \hline

\end{tabular}\)

from statement 2) we get no additional information that is useful

therefore A

hope that helps

-buff