twelve men take 6 hours to finish a piece of work. after the 12 men have worked for 1 hour, the contractor decides to call in 8 more men to complete the remaining work. how many more hours would the 20 men take to complete the remaining piece of work?

is this correct?
12 men 6 h 1 job.
12 men 5 h 5/6 job
20 men ?h 5/6 job

x/5 = 12/20
x= 3h

yes this is correct

fantastic

Yes, your calculation is correct.

Given that 12 men can complete the work in 6 hours, we can calculate that they can complete 1/6th of the work in 1 hour.

After working for 1 hour, the 12 men have completed 1/6th of the work, leaving 5/6th of the work remaining.

When the contractor calls in 8 more men, the total number of men becomes 20.

Let's assume that it will take x hours for the 20 men to complete the remaining 5/6th of the work.

Since we know that 12 men can complete 5/6th of the job in 5 hours, we can set up a proportion:

12 men / 5 hours = 20 men / x hours

Cross multiplying gives us:

12x = 5 * 20

Simplifying further:

12x = 100

Dividing both sides by 12:

x = 100 / 12

So, the 20 men would take approximately 8.33 hours (rounded to two decimal places) to complete the remaining piece of work.

Yes, your calculation is correct. Let's break it down step by step:

We know that 12 men can complete a piece of work in 6 hours. This means that in 1 hour, 12 men can complete 1/6th of the work.

After the 12 men have worked for 1 hour, they have completed 1/6th of the work, leaving 5/6th of the work remaining.

Now, the contractor calls in 8 more men, making the total number of men working on the remaining task to be 12 + 8 = 20 men.

We want to find out how many more hours it will take these 20 men to complete 5/6th of the work.

To do this, we can use the formula:

(number of men) * (number of hours) = (fraction of work completed)

Plugging in the values, we have:

20 * x = 5/6

To solve for x (the number of hours), we need to divide both sides of the equation by 20:

x = (5/6) / 20

Simplifying further:

x = 5/6 * 1/20

x = 5/120

x = 1/24

So, the 20 men would take 1/24th of an hour to complete the remaining 5/6th of the work.

Converting 1/24th of an hour to minutes, we get:

1/24 * 60 = 2.5 minutes

Therefore, the 20 men would take an additional 2.5 minutes to complete the remaining piece of work.