Problema Solution
Emily rows six miles down stream in 1 hour and her friend Ashley,rowing 1 mile faster per hour completes the return trip in 2 hours.
(a)Find the speed of the current (c) and each girl's rowing speed?
(b)If emily and Ashley were rowing separately, who would complete their trip first and by how long? Round to the nearest hundredth, if necessary.
Answer provided by our tutors
Let the speed of current be x mph
Let Emily's speed in still waters be a mph
DOWNSTREAM
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Emily's speed = (a + x) = 6 /1 = 6
UPSTREAM
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Ashley's speed = (a +1 - x) = 6/2 = 3
a + x = 6
a - x = 2
ADD
2a = 8
a = 4
x = 2
ANSWER speed of current = 2 mph Emily's speed = 4 mph Ashley's speed = 5mph
Emily = 1 + 3 = 4 hours
Ashley = 6/7 + 2 = 2.86 hours
ANSWER Ashley will finish first and 1.14 hours earlier