Toms dr. told him that he should lose 15 pounds he weighs 285 pounds what percent should his weight decrease at?

Multiply. write your answer in simplest form. 3/8 x 5/7

How do you solve a question like this?

Jack has a piece of red ribbon that is two times as long as his piece of blue ribbon. he says that he can use two different equation to find out how long his piece of red ribbon is compared to his piece of blue ribbon is. is he correct? explain his reasoning