"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 ?
To solve a ratio word problem, you need to first identify the given information and the unknown quantities. Then, set up a ratio equation using the given information and solve for the unknown quantity using basic algebraic operations.
Solving ratio word problems is important in many fields, including science, finance, and everyday life. It helps to compare and analyze quantities in relation to each other, make predictions, and make informed decisions based on the given information.
Sure, for example, if A can do a job in 30 days and B can do the same job in 40 days, how long will it take them to do the job together? First, set up the ratio equation: A/B = 30/40. Then, cross multiply to get 40A = 30B. Simplify to get A = 3B/4. This means that A can complete 3/4 of the job in the same time it takes B to complete the whole job. Therefore, it will take A and B together (3/4 + 1) = 7/4 of the time it takes B alone, or (7/4) x 40 = 70 days.
Some tips for solving ratio word problems include setting up a clear and organized ratio equation, understanding the relationship between the quantities, and using basic algebraic operations to solve for the unknown quantity. It can also be helpful to use diagrams or tables to visualize the problem and keep track of the given information.
Solving ratio word problems can be useful in analyzing and comparing quantities in scientific research. For example, it can be used to calculate ratios of different substances in a chemical reaction, compare the effectiveness of different treatments or doses in a medical study, or analyze the ratio of different variables in a biological system. It can also help in making predictions and drawing conclusions based on the given information.