The problem involves determining how long A and B will take to complete a job when working together, given that A can complete the job in 30 days and B in 40 days. The discussion revolves around understanding work rates and the implications of combining their efforts.
Participants are actively engaging with the problem, with some expressing confusion over initial calculations and questioning the logic behind the results. There is a recognition of the need to analyze the rates of work for both individuals, and some guidance is offered on how to set up the equations for their combined work.
Some participants mention specific answers from their notes, indicating a potential discrepancy in understanding the problem setup or calculations. The discussion reflects a mix of interpretations and approaches to the problem, with no clear consensus yet on the correct method or final answer.
"painting" ?alijan kk said:Homework Statement
A can do a piece of work in 30 days while B can do it in 40 days. In how many days can A and B working together do it ?
Homework Equations
The Attempt at a Solution
I just imagined walls and paiting work and try to assign them
Does this make sense? B working alone can do the work in 40 days. Why would it take 15 days longer if both of them are workingalijan kk said:and i found that it tooks 55 days working together ?
Look at the problem in terms of what each person can do in one day. A can do 1/30 of the job per day, and B can do 1/40 of the job. How much can they do together in a day?alijan kk said:but i don't know how can i approach this kind of problems
and in my notes the ans is 17+1/7 days
Mark44 said:"painting" ?
Does this make sense? B working alone can do the work in 40 days. Why would it take 15 days longer if both of them are working
Look at the problem in terms of what each person can do in one day. A can do 1/30 of the job per day, and B can do 1/40 of the job. How much can they do together in a day?
A does 1/30 job a day and b does 1/40 job a day,,,,, should i sum up the 1/30 and 1/40 to get the joint working job per day ration ?Chestermiller said:This is basically a rate-time-distane problem. If it takes A 30 days to do a job working alone, what is his rate of doing work, in jobs/day. If it takes B 40 days, what is his rate of doing work, in jobs/day. How many jobs does A do in t days? How many jobs does B do in t days? How many jobs do A and B do together in t days?
Please answer my other questions. You're on the right track.alijan kk said:A does 1/30 job a day and b does 1/40 job a day,,,,, should i sum up the 1/30 and 1/40 to get the joint working job per day ration ?
t/30 A and t/40 BChestermiller said:Please answer my other questions. You're on the right track.
Let t = number of hours for A and B working together to finish the job.alijan kk said:A does 1/30 job a day and b does 1/40 job a day,,,,, should i sum up the 1/30 and 1/40 to get the joint working job per day ration ?