Bunuel
There is a certain number of students in Mr. Stewart’s class. Could Mr. Stewart evenly divide the class into 3 study groups?
(1) If Mr. Stewart reduced the number of students in his class by 16 percent he could evenly divide the class into groups of 9.
(2) If Mr. Stewart reduced the number of students in his class by 6 percent he could evenly divide the class into groups of 3.
We need to know whether \(s\) is a multiple of \(3 \)
\(s =\) # of students hence \(s\) needs to be an integer.
(1) If Mr. Stewart reduced the number of students in his class by 16 percent he could evenly divide the class into groups of 9.\(\frac{84}{100}*s = 9*y \)
\(s= \frac{9*y}{84}*100\)
\(s= \frac{ 3 * y}{7}*25\)
Since \(s\) is an integer \(y\) has to be a multiple of \(7\) , so we can remove the \(7\) from the denominator
\(s=3*25 \)
We can ans YES to the stem as \(s\) is a multiple of \(3 \)
SUFF.(2) If Mr. Stewart reduced the number of students in his class by 6 percent he could evenly divide the class into groups of 3\(\frac{94}{100}*s = 3*y \)
\(s= \frac{3*y}{94}*100\)
\(s= \frac{3*y}{47}*50\)
Since \(s\) needs to be an integer \(y\) is a multiple of \(47 \), hence the \(47\) in the denominator gets cancelled out.
\(s=3*50 \)
We can ans YES to the stem as \(s\) is a multiple of \(3 \)
SUFF.Ans D
Hope it helps.