traveling 60 mph increase to 70mph for 400 mile took 6 hrs how long did it take?

Answer 1

Do you mean how far did the traveler travel?

If the traveler traveled 400 miles at a speed of 70mph, then the travel time at this speed is:
Travel time @ 70mph = 400/ 70
Travel time @ 70mph = 5∙714 285 714 hours.

Total travel time is 6 hours (given).
6 - 5∙714 285 714 = 0∙285 714 285 hours @ 60mph.
Distance = Speed x time
Distance = 60 x 0∙285 714 285
Distance = 17∙142 857 14

Total distance = 600 + 17∙142 857 14
Total distance = 617∙142 857 14
Total distance ≈ 617∙14

Answer 2

Divide 2100 by 60

Answer 3

It took 6 hours.