Problema Solution
Flying against the jetstream, a jet travels 2940 miles in 3 hours. Flying with the jetstream, the same jet travels 8400 miles in 6 hours. What is the rate of the jet in still air and what is the rate of the jetstream?
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et
p = the jet's rate in still air
w = the rate of the jetstream
d1 = 1940 miles flying against the jetstream
t1 = 3 hour flying against the jetstream
d2 = 8400 miles flying with the jetstream
t2 = 5 hours flying with the jetstream
the rate of the jet flying against the jetstream is: p - w
the rate of the jet flying with the jetstream is: p + w
since rate = distance/time => distance = rate*time
the jet flying against the jetstream
d1 = (p - w)t1
(p - w)3 = 2940 divide both sides by 3
p - w = 980
the jet flying with the jetstream
d2 = (p + w)t2
(p + w)6 = 8400 divide both sides by 6
p + w = 1800
by solving the system of equations
p - w = 980
p + w = 1800
we find
p = 1390 mph
w = 410 mph
click here to see the step by step solution of the system of equations
the rate of the jet in still air is 1390 mph.
the rate of the jetstream is 410 mph.