Isabelle and her friend Tisha are knitting scarves for the homeless. Isabelle had already completed 7 scarves and has committed to making 1 more scarf per day. Tisha, who hasn't completed any scarves yet, has more free time and can make 8 scarves per day. At some point, Tisha will catch up and they will both have completed the same number of scarves. How many scarves will each woman have finished? How long will that take?