SOLUTION: A painting job can be completed by 3 painters in 17 days. If 12 more painters join the team 2 days after starting work on the job, then how many more days are required to complete

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A painting job can be completed by 3 painters in 17 days. If 12 more painters join the team 2 days after starting work on the job, then how many more days are required to complete      Log On


   

Question 947264: A painting job can be completed by 3 painters in 17 days. If 12 more painters join the team 2 days after starting work on the job, then how many more days are required to complete the job?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
What fraction of the job can the +3+ painters
get done in +2+ days?
They can do +2%2F17+ of the job
That leaves +15%2F17+ of the job left to do
----------------------------------------
It is assumed ( but they don't say it ) that the
extra +12+ painters work at the same rate as
the first +3+
-------------------
There are +3+%2B+12+=+15+ painters total after
the 1st 2 days
-------------------
+15+=+3%2A5+
+5+ times as many painters can work at
+5+ times the rate, so their rate is
( 1 job ) / ( 17/5 days ) = +5%2F17+
Now I can say:
+5%2F17+=+%2815%2F17%29+%2F+t+ ( t is time in days )
Multiply both sides by +17t+
+5t++=+15+
+t+=+3+
3 days are required to finish the job
hope I got it