posted by karon on .
jack usually mows his lawn in 4 hours mariltn can mow the same yard in 7 hours how much time would it take for them to mow the lawn together
In 28 hours, Jack can do 7 lawns, and mariltn can do 4, so combined, in 28 hrs, they can do 11 lawns.
rate combined: 11/28 lawns per hour
time= 1lawn/rate= 28/11 hours.