I need help with this question fast!!!!

Question

Brian gets pic 'n mix when at the cinema and makes his bag up with 3 types of sweet. He picks 3 times as many smarties as cola bottles. He also picks twice as many marshmallows as smarties. What proportion of the bag of sweets are cola bottles? 

Give your answer in its simplest form.

Answer 1

b represents number of bottles

3b represents the number of sweeties

6b represents the number of marshmallows

1 : 3 : 6

"proportion of the bag of sweets are cola bottles?" does not make sense.