I have 3 types of shapes: triangle, square or circle in the ratio 3:6:1. The triangles are either red or blue. The ratio of red triangles to blue triangles is 4:5. Given that I have 12 red triangles, how many circles are there

ok first lets take care of the color
given that you have 12 red triangles and the ratio for red triangles to blue triangles is 4:5
if 12=4 than blue=5
12 times 5= 60
12 times 4 = 48
48 red and 60 blue = triangles
48+60=108
there are 108 triangles in total
now since the ratio for triangle square or circle is 
for every 3 triangles there are 6 squares and for every six squares there is one circle
t3:s6:c1
since there are 108 triangles
108/3=36
since for every 3 triangles there are 6 squares 
six times 36(amount of triangles/3)
6*36+=216
so there are 216 squares
now it says for every six squares there is one circle
therefor (the amount of squares)216/6+= 36 
we are back to 36 and there are 36 circles