Respuesta :
Answer:
It will take 4.5 hours for rick to complete the job.
Step-by-step explanation:
Given:
Time taken by Phil to paint the garage = 12 hours.
It means that for each hour he does = [tex]\frac{1}{12}[/tex]of the job.
.
Time taken by Rick to paint the garage = 10 hours.
It means that for each hour he does = [tex]\frac{1}{10}[/tex] of the job
.
If they work together for 3 hours,
Phil does job in 3 hrs = [tex]3\times\frac{1}{12} = \frac{1}{4}=0.25[/tex]
Rick does job in 3 hrs = [tex]3\times\frac{1}{10} = \frac{3}{10}=0.3[/tex]
.
So in three hours of working together job done = [tex]0.3+0.25 = 0.55[/tex]
.
This means job of the painting entire garage have been done 0.55 of it.
1 - 0.55 = 0.45.
So there is 0.45 job left
At this point Phil quits and Rick presses on by himself. Since he does 1/10 of the garage every hour
Let T represents the time that Rick needs to complete the job after Phil leaves.
Hence, [tex]\frac{1}{10}\times T= 0.45\\\\T = 0.45 \times 10\\T =4.5 hrs[/tex]
Hence it will take rick 4.5 hours to complete the remaining job.
