If the average of m number is n^{2 }and that of n number is m^{2} then the average of (m + n) numbers is 

a) 
mn 
b) 

c) 
mn 
d) 
m+n 
If the average of m number is n^{2 }and that of n number is m^{2} then the average of (m + n) numbers is 

a) 
mn 
b) 

c) 
mn 
d) 
m+n 