Question

Roger can run one mile in 6 minutes. Jeff can run one mile in 4 minutes. If Jeff gives Roger a 1 minute head start, how long will it take before Jeff catches up to Roger? How far will each have run?

Answer 1

Roger speed 1/6 mile/min
Jeff speed 1/4 mile/min

Set Jeff catch Roger at x， time t
X= 1/6*t
X=1/4*（t-1）
=> 1/6*t=1/4(t-1）
4t=6t-6
t=3
X=1/2