The contractors Brent and Garth always start their jobs at 9:00am. If Brent works alone, he will finish at 5:00pm, including an hour-long lunch.If Garth works alone, he will finish at 3:00pm, including an hour-long lunch. If they work together, they will have an hour-long lunch instead. Assuming the rate at which they work stays the same, at what time in the afternoon will they finish? Please give the answer in the 12-hour format xx:yy, rounded to the nearest minute (e.g.02:12).

Guest Mar 9, 2022

#1**+1 **

If they work together, they will have an hour-long lunch instead. ???? Is this part correct?

ElectricPavlov Mar 9, 2022

#2**0 **

If I understand this correctly......

Not counting lunch, it takes Brent 7 hrs to do the job alone and Garth 5 hrs to do the job alone

Working together they completete (1/7 + 1/5) = 12 / 35 of the job each hour

So.......they will take 35 / 12 hrs to do the job working together ≈ 2.916 hrs

So .916 * 60 ≈ 55 min

So.....working together.......they would finish the job at ≈ [ 9 + 2 ] hrs + [ 55 min ] ≈

11 : 55 AM [ with no lunch ]

12: 55 PM [ if they take a lunch break any time before 11 : 55 AM ]

CPhill Mar 9, 2022