Three typists working 8 hours a day type a document in 10 days. If only 2 typists are working, how many hours a day should they work to finish the job in 12 days.

the job takes 3*8*10=240 typist-hours.

2 typists working x hours per day perform 2x typist-hours per day.

So, 2x*12 = 240
x = 10 hours per day

To solve this problem, let's first calculate the total amount of work required to complete the document.

Since three typists working 8 hours a day can finish the document in 10 days, we can calculate the total amount of work as follows:

Work done by three typists in one day = 3 typists * 8 hours/day = 24 hours
Total work done by three typists in 10 days = 24 hours/day * 10 days = 240 hours

Now, with only 2 typists, let's calculate the number of hours they need to work per day to finish the document in 12 days:

Work done by two typists in one day = 2 typists * x hours/day (where x is the number of hours they work per day)
Total work done by two typists in 12 days = 2 typists * x hours/day * 12 days = 24x hours

Since the total amount of work remains the same (240 hours) for both scenarios, we can equate the two expressions:

240 hours = 24x
x = 240 hours / 24
x = 10 hours

Therefore, the two typists should work 10 hours a day in order to finish the job in 12 days.

To answer this question, we can use the concept of "person-hours" or the amount of work done by one person in one hour.

First, let's calculate the amount of work required to complete the document. Since three typists working 8 hours a day take 10 days to finish the job, the total work done is calculated as follows:

3 typists * 8 hours/day * 10 days = 240 person-hours

Now, we need to determine how many person-hours per day are required if only 2 typists are working and the job needs to be completed in 12 days. We can use the formula:

(person-hours required) = (number of typists) * (hours per day) * (number of days)

Knowing that we need to complete the job in 12 days and that only 2 typists are available, we can calculate the number of hours per day as follows:

(person-hours required) = 2 typists * (hours per day) * 12 days

Since the amount of work required is the same (240 person-hours), we can set up an equation:

240 person-hours = 2 typists * (hours per day) * 12 days

Now, we can solve this equation to find the number of hours per day that the 2 typists should work:

(hours per day) = (240 person-hours) / (2 typists * 12 days)
(hours per day) = 240 / 24
(hours per day) = 10

Therefore, the two typists should work 10 hours per day to finish the job in 12 days.

10hours