The reeds are moving cross country Mr reed leaves 35 hrs bef

The reeds are moving cross country. Mr reed leaves 3.5 hrs before mrs reed. If he averages 40 mph and she averages 75 mph, how long will it take mrs reed
to overtake mr reed?

Solution

leads by 3.5*40=140 miles
overtake speed is 35 mph
140/35=4 hrs