Molly shared a spool of ribbon with 12 people. Each person received 3 feet of ribbon. Which equation can she use to find r, the number of feet of ribbon that her spool originally had?

For this case we have that if Molly spent all the spool ribbon with 12 people, then "r" would be given by the product of 12 for the amount of ribbon that each person received, that is:[tex]r = 12 * 3\\r = 36 \ft[/tex]Thus, the spool initially had 36 feet of ribbon.If Molly also keeps 3 feet of ribbon, then the value of "r" is given by:[tex]r = 13 * 3\\r = 39 \ ft[/tex]In this case, the ribbon spool initially had 39 feet of ribbon.Answer:[tex]r = 36 \ ft[/tex]shared between 12 people[tex]r = 39 \ ft[/tex]shared between 12 people and Molly