3 hrs = 180 minutesHello,

Will anyone help me with this word problem?

Two drivers, starting at the same place, begin driving in opposite directions at the same time. One heads east at 65 kilometers an hour and the other heads west at 85 kilometers an hour.will they be 450 kilometers apart?In how many minutes

How do we set this system of equations up? Will the answer be 3 minutes or 3 hours? On my test, I marked 3 hours and it was wrong. Please help me. Thanks so much in advance.