1/4 of all the juniors and 2/3 of all the seniors are going on a trip. If there are 2/3 as many juniors as seniors, what fraction of the students are not going on the trip? Choose the correct choice from the following options: A) 4 / 9 B) 1 / 2 C) 2 / 3 D) 1 / 3 E) 5 / 6

Rationale: j be the number of juniors and s be the number of seniors . there are 2 / 3 as many juniors as seniors 23 ∗ s = j j / s = 23 going on trip = j 4 + 23 ∗ s fraction = ( j 4 + 23 s ) / ( j + s ) = ( 2 / 3 * 1 / 4 + 2 / 3 ) / ( 2 / 3 + 1 ) = 1 / 2 fraction not on trip = 1 / 2 answer : b
Answer: B