Replace the question marks in the line below.
Beth : 1 job in 6 hours.
Abby : ? jobs in ? hours.
The answer is 1 however i am getting 0.75. Could anyone tell me where i am going wrongIn one half the time Abby can produce three times as much work as Beth. Beth can do in twice the time 1/3 as much work as carol. If carol does a job in one hour , how many hours will it take Abby to do the same job. ?
Solution:
Beth:
Beth thus
1/3 of work in 2 hours
so for one job it takes 6 hours.
Abby:
6 * (2/3) = 4 hours.
So in 4 hours Abby does 3 jobs
so 1 job takes 3/4 hours.
carol does (1 job)/(1 hr)In one half the time Abby can produce three times as much work as Beth. Beth can do in twice the time 1/3 as much work as carol. If carol does a job in one hour , how many hours will it take Abby to do the same job. ?
beth does (1/3 job)/(2 hrs)
abby does (3 * 1/3)/(1/2 * 2) = (1 job)/(1 hr)
Yet another variation:
"carol does a job in one hour"
"Beth can do in twice the time 1/3 as much work as carol."
So in 2 hours Beth does 1/3 the job. It would take her 6 hours to do the job.
"In one half the time Abby can produce three times as much work as Beth."
So in 3 hours, Abby can do the job three times. She can do the job once in one hour, just like Abbey.
From a purely "mathematical" point of view "twice the time" and "one half the time" cancel while "1/3 as much work" and "three times as much work" cancel.
Your error was in converting "In one half the time Abby can produce three times as much work as Beth." into "2/3" Beth's time per job. In fact it should be "1/2 Beth's time" times "1/3 job"= "1/6 Beth's time per job".
first find how much beth can produce in 2 hours , which can be done by ratio and proportion.that would be 4/3. this is one third of how much carol produces in one hour. if this is one third carol can produce 4 units in one hour. so in order to gain 4 units beth shoud work 3 two hours which is also "6 hours"