9 men build a house in a working 4 days .how many workmen ,working at the same rate willbe needed to build a house in 3 days
9 men do the job in 4 days
That means 9 men can do 1/4 the job in 1 day.
So, each man can do 1/36 of the job in a day.
So, each man can do 3/36 = 1/12 the job in 3 days
So, it will take 12 men to do the job in 3 days
Or, more succinctly, since we want to take 3/4 as long, it will take 9/(3/4) = 12 men
18-10x<-22
To solve this problem, we can use the concept of man-days of work. Man-days is a measure that combines the number of workers and the number of days worked to quantify the total amount of work done.
In the given situation, 9 men built a house in 4 days. This means they worked a total of 9 * 4 = 36 man-days to complete the house.
Now, let's calculate how many workmen would be needed to build a house in 3 days, while working at the same rate.
Since we want to complete the house in 3 days, the total man-days required would be 36 (same as before).
If X represents the number of workmen needed for 3 days, we can set up a proportion:
Number of workmen / Number of days = Number of workmen / Number of days
9 / 4 = X / 3 (equating the two proportions)
To find X, we cross-multiply:
9 * 3 = X * 4
27 = 4X
Divide both sides by 4:
27 / 4 = X
X ≈ 6.75
Since we cannot have a fraction of a workman, we need to round up to the nearest whole number. Therefore, we would need at least 7 workmen to build the house in 3 days, assuming they work at the same rate as the original 9 men.