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