You can put this solution on YOUR website! i believe 1:4.
there are 3 b's for every a.
there are 4 c's for every 3 b.
it would be a direct substitution.
3b = 1a.
if b:c were 1:4 it would be a different story.
then the ratio would be probably 1:12 since for every 1a there would be 3b and for every 1b there would be 4c so 3b would equate to 12c.