Doctors and Lawyers

The average (arithmetic mean) age of a group of doctors and lawyers is 40. If the doctors average 35 years of age and the lawyers average 50 years of age, then the ratio of the number of doctors to the number of lawyers is:

  1. 3:2
  2. 3:1
  3. 2:3
  4. 2:1
  5. 1:2


Show/Hide Solution

Let’s have D doctors. If their average age is 35, the total of their ages is 35D. And for L lawyers, the total of their ages is 50L. The average for all of them is 40:

(35D + 50L) / (D + L) = 40
35D + 50L = 40(D + L)
35D + 50L = 40D + 40L
50L – 40L = 40D – 35D
10L = 5D => 10/5 = D/L = 2:1

The answer is d.

Leave a Reply

Your email address will not be published.