Let time taken to fly 1,200 miles, be T
Then time taken to fly 480 miles = T - 3
Since speed was same for both distances, then we can say that:
1,200(T – 3) = 480T ----- Cross-multiplying
1,200T – 3,600 = 480T
1,200T – 480T = 3,600
720T = 3,600
T, or time taken to fly 1,200 miles =, or hours
Time taken to fly 480 miles: 5 – 3, orhours