The average age of doctors and lawyers together is 40. If the doctors average age is 35 and the lawyers average age is 50, then find the ratio of the number of doctors to the number of lawyers.

        Number of lawyers $=y$

By the date, Sum of age of x doctors $=35x$

                    Sum of age of y lawyers $=50y$

$\frac{Sumofageofxdoctors+Sumofageofylawyers}{x+y}=40$

$\frac{35x+50y}{x+y}=40$

$\Rightarrow 10y=5x$

$\Rightarrow x/y=2/1$

$x:y=2:1$