Problema Solution
Sarah starts riding her bike at a rate of 10 miles per hour. After 5 minutes, Cara starts riding from the same starting point as Sarah and along the same route at a rate of 12 miles per hour. If each girl rides at a constant rate how many minutes will Sarah ride his bike before Cara catches up wit her?
Answer provided by our tutors
let
v1 = 10 mph the rate of Sarah
v2 = 12 mph the rate of Cara
t = the time of the ride of Sarah in hours
t - 5/60 = the time of the ride of Cara in hours
since the both do the same distance and distance = rate*time we have
v1*t = v2(t - 5/60)
10t = 12(t - 5/60)
by solving we find
t = 0.5 hr = 0.50*60 min
t = 30 min
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Sarah will ride 30 min before Cara catches up.