alg 2 word prob

Question

lucas spent the first 120 miles of a road trip in traffic. when the traffic cleared, he was able to drive fast for the remaining 300 miles. if the total trip took 9 hours, then how fast was he traveling in traffic?

Answer 1

some information is missing, such as the speed the last 300 miles

assume that's 60 mph, then it took 300/60 = 5 hours

and 9-5 = 4 hours to go 120 miles at 120/4 = 30 mph in traffic