Need help pls and thank u

An arc subtends a central angle measuring 7pi/4 radians what fraction of the circumference is this arc?

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?

On ryan's last social studies test there were two types of questions true/false worth 3 points each and multiple choice questions worth 4 points each