SOLUTION: ) P&Q can harvest a field in 5 & 7 days respectively. After p has worked for 3 days , he is joined by Q. in how many more days will the work be completed?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: ) P&Q can harvest a field in 5 & 7 days respectively. After p has worked for 3 days , he is joined by Q. in how many more days will the work be completed?      Log On


   

Question 839212: ) P&Q can harvest a field in 5 & 7 days respectively. After p has worked for 3 days , he is joined by Q. in how many more days will the work be completed?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
P&Q can harvest a field in 5 & 7 days respectively.
After p has worked for 3 days , he is joined by Q.
in how many more days will the work be completed?
:
Let t = time to complete the job. (also time worked by Q)
then
(t+3) = time worked by P
:
Let the completed job = 1
:
Each will do a fraction of the job, the two fractions add up to 1
:
%28%28t%2B3%29%29%2F5 + t%2F7 = 1
multiply equation by 35, cancel the denominators.
7(t+3) + 5t = 35
7t + 21 + 5t= 35
7t + 5t = 35 - 21
12t = 14
t = 14/12
t = 11%2F6 days to complete the job
:
:
Check on calc (P works 41%2F6 days)
4.17%2F5 + 1.16%2F7 =
.834 + .166 = 1