Sue can shovel snow from her driveway in 35 minutes. Bill can do the same job in 40 minutes. How long would it take SueSue and BillBill to shovel the driveway if they worked together?
Sue can shovel snow from her driveway in 35 minutes. Bill can do the same job in 40 minutes. How long would it take SueSue and BillBill to shovel the driveway if they worked together?
Sue can shovel snow faster than Bill?
Sue can finish 1/35 of the job in 1 minute.
Bill can finish 1/40 of the job in 1 minute.
1/35 + 1/40 =3/56 Their combined rate in 1 minute. Therefore, both working together can finish th job in:56/3=18 2/3 minutes.
+37103 Look at it as a RATE problem......
One job = 1
Bill's rate = 1/40 job/minutes
Sue's rate= 1/35 job/minutes
What is the RATE when they BOTH work ?
(1/40 + 1/35) job/minutes = (7+8)/120 = 15/280 Job/minutes
the TIME to complete ONE job = ONE Job / RATE so, substitute:
1 Job / (15/280 Job/Minutes) = 280/15 minutes = 18.67 minutes
