two complementary angles are in the ratio 3:2

1) x/y = 3/2 
or (2/3)x=y 

2) x+y=90 

together 
x + (2/3)x=90 
5/3 x = 90 

(3/5)(5/3)x=(3/5)*90 
x=54 
thus y=36 

:)