How many minutes of news would the disc jockey have to play for every 60minutes of music

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?

Combine like terms to make a simpler expression 3z+z

What is the gcf of 20c^3-5c^4+30c^6