6th grade story problem help

Question

If Mrs Taylor is making identical costumes and has 126 pink ribbons and 108 yellow ribbons. What is the maximum number of costumes can she make?

How many pink and yellow ribbons are on each costume?

Answer 1

The number of identical costumes shall be the greatest common factor, GCF, of 126 and 108.

 

The prime factors of 126: 2·3²·7

The prime factors of 108: 2·3³

 

GCF is 2·3² or 18.

 

She can make 18 identical costumes.

 

How many ribbons are on each?