Problema Solution
Jeff and Kirk can build a 75-ft retaining wall together in 55 hours. Because Jeff has more experience, he could build the wall by himself 33 hours quicker than Kirk. How long would it take Kirk (to the nearest minute) to build the wall by himself?
Answer provided by our tutors
Let
x = the hours that Jeff needs to build the wall alone thus his rate is 1/x walls per hour, x>0
x + 33 = the hours that Kirk need to build the wall alone this his rate is 1/(x + 33) walls per hour
Jeff and Kirk can build a 75-ft retaining wall together in 55 hours follows their together rate is 1/55 walls per hour:
1/x + 1/(x + 33) = 1/55
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click here to see the equation solved for x
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x = 95.9217 hr
x = 95 hr 0.9217*60 min
X = 95 hr 55 min
Kirk will need 95 hr 55 min to build the wall alone.