21) on the first day of his cross-country trip, mike drove 100 miles in 2 hours before stopping for lunch. after lunch, he drove 420 miles in 6 hours. what was average speed in miles per hour for his 8 hours of driving

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. what distance from city a is the point where the truck and the car will meet?