Question

Jack and Jill are brother and sister. Jack rakes the yard in 5 hours and Jill rakes the yeard in 8 hours. Mom says to rake the yard together how long will that take? ( answer as a mixed fraction)

Answer 1

Given that Jack rakes the yard in 5 hours and Jill rakes the yeard in 8 hours. Let the amount of time that it takes them to rake the yard together be t, then:


`(1)/(t) = (1)/(5) + (1)/(8) \\ \\ = (8+5)/(40) = (13)/(40) \\ \\ \therefore t= (40)/(13) =3 (1)/(13)\ hours`