Problema Solution
Mike and Dan are mowing a lawn. If Mike mows the lawn by himself, it takes him 3 more hours than it would take if Dan mows the lawn by himself. If they can mow the lawn in 7 hours by working together, how long does it take Mike to mow the lawn?
Answer provided by our tutors
let
x = the hours Mike needs to mow the lawn alone
y = the hours Dan needs to mow the lawn alone
x = y + 3
if they mow together they finish the job in 7 hours
1/x + 1/y = 1/7
by solving the system of equations
x = y + 3
1/x + 1/y = 1/7
we find
x = 15.6589 hours
y = 12.6589 hours
Mike needs 15.6589 hours to mow the lawn alone and Dan needs 12.6589 hours to mow the lawn alone.