What is the correct option to this Anwser

Describe all the numbers that when rounded to the nearest thousand are 645,000

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

If there are 3.281 feet in 1 meter, how many inches are in one centimeter