What is the answer?

Question

martin drove from miami to orlando a total distance of 240 miles. He drove for 1 hour in city traffic and for 3 hours on the highway, If his average speed on the highway was 20 miles per hour faster than his speed in the city, determine his average speed driving in the city and his average speed driving on the highway

Answer 1

240/4 = 60 mph average speed, 240/3 = 80>H>60, 40<C<60

H=20+C

3H+ C = 240

3(20+C)+C = 240

4C =240-60 = 180

C= 180/4 = 45 mph in the city

H = 65 mph on the highway

3(65) + 1(45) = 195 +45= 240 miles