at 700am Joe starts jogging at 6mih At 710am Ken starts off

at 7:00a.m. Joe starts jogging at 6mi/h. At 7:10a.m. Ken starts off after him. How fast must Ken run in order to overtake him at 7:30a.m.?

10 min = 1/6 hour
Joe goes 1 mile in 1/6 hour - he\'s one mile ahead.
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To overtake him in 20 minutes (1/3 hour) Ken has to go 3 mph faster (1 mile in 1/3 hour = 3 mph)
Ken has to go 9 mph