The age distribution of 400 persons in a colony having median age 32 is given below:  

Age (in years) :	20-25	25-30	30-35	35-40	40-45	45-50
Frequency:	110	x	75	55	y	30

Then,  $x -y$ is 

The cumulative frequency distribution is 

Clearly  $270+x+y=400\Rightarrow x+y=130$

It is given that 32 is the median. So, 30 - 35 is the median class

 such that 

     $l=30,h=5,f=75,N=400$ and $,F=110+x$

             $\begin{array}{l}\therefore \hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\text{ Median }=l+\frac{\frac{N}{2}-F}{f}\times h\\ \Rightarrow \hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}32=30+\frac{200-(110+x)}{75}\times 5\\ \Rightarrow \hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}2=\frac{90-x}{15}\Rightarrow x=60\\ \therefore \hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}x+y=130\Rightarrow y=70\end{array}$    

     Hence, $x-y=-10$