GeminiHeat wrote:
In a certain class of students, 25% received A’s on the final exam and 2/3 of these students received A’s in the class as a whole. If 15 students in the class received A’s on the final exam but did not receive an A in the class, how many students did not receive an A on the final exam?
A. 45
B. 60
C. 105
D. 135
E. 180
Let the total number of students in the class be \(x\)
Students with A \(= 0.25x\)
Students with not an A \(= 0.75x\)
Now, Students with an A in the class \(= \frac{2}{3}(0.25x)\)
So, Students with not an A in the class \(= \frac{1}{3}(0.25x) = 15\)
\(0.25x = 45\)
\(x = 180\)
Therefore, Students with not an A \(= 0.75x = 0.75(180) = 135\)
Hence, option D