Problema Solution
Roger can run one mile in 15 minutes. Jeff can run one mile in 12 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 to run?
Answer provided by our tutors
let
v1 = 1/15 miles per min the average speed of Roger
v2 = 1/12 miles per min the average speed of Jeff
t = the time in minutes that Jeff runs before catches up to Roger
t + 1 = the time in minutes that Roger runs before Jess catches up with him
since the both run the same distance and distance = speed*time we have
v1*(t + 1) = v2*t
(1/15)(t + 1) = (1/12)*
by solving we find
t = 4 min
click here to see the step by step solution of the equation
the distance each of them runs is v2*t = (1/12)*4 = 1/3 mile = 0.33 mi.