Question

Mr warren drove from Townsville to villaville at 70 mph and back again at a speed of 50 mph. His total driving time was 12 hours. How far apart are the two towns

Answer 1

Warren drove from Townsville  à Villaville at 70 miles per hour
and from Villaville to Townsville è  50 miles per hours
He drove for a total of 12 hours.
=> 70 miles + 50 miles = 120 miles
=> 12 hours
So the unit rate of his driving is 120 miles / 12 hours
=> 120 miles  / 12 hours
=> 10 miles / hour
thus, he drove in total for 10 miles per hour.
And probably the 2 towns are about 60 miles away.

Answer 2

Call the distance between the towns 'D' .

The time it takes to cover a distance is (distance) divided by (speed).

It takes Mr. Warren  D/70  hours on the first trip,
and it takes him  D/50  hours on the return.
All together, it takes him 12 hours.

                                                    D/70 + D/50         =  12 hours

Change the fractions to
a common denominator
(350) for adding:                  5D / 350 + 7D / 350  =  12

Add:                                              12D / 350           =  12

Divide each side by  12 :               D / 350             =  1

Multiply each side by  350 :              D                    =  350 miles .

Check:

Going:        350mi / 70 mph = 5 hours

Coming:     350mi / 50 mph = 7 hours

Total                                          12 hours            yay !