SAT Math Multiple Choice Practice Question 163: Answer and Explanation
9. The ratio of seniors to juniors in a certain club is 5:3. If there are 40 students in the club, then the number of juniors is
Correct Answer: B
B. As I'm sure you remember, in ratio problems the total number of objects (students, in this case) must be divisible by the sum of the numbers in the ratio (5 + 3 = 8). Specifically, you can call the number of seniors 5x and the number of juniors 3x, and write 5x + 3x = 40, which gives you x = 5. Plugging that number back in to the equation gives you 25 seniors and 15 juniors.