Question 1106037
<br>
This is essentially a mixture problem; you are mixing doctors and lawyers and getting an average age of the whole group.<br>
Here is an easy way to solve mixture problems....<br>
(1) The overall average age of 40 is "twice as close" to the average age of the doctors (35) as it is to the average age of the lawyers (50):
That is, 50-40=10; 40-35=5.  5 is half of 10; so 40 is twice as close to 35 as it is to 50.
(2) That "twice as close" means the number of doctors has to be twice the number of lawyers.<br>
So the ratio of the number of doctors to the number of lawyers is 2:1.