Let d represent number of days and n represent number of workers.
We have been given that when building a house, the number of days required to build varies inversely with with the number of workers.
We know that the equation
represents the relation where y is inversely proportional to x and k is the constant of proportionality.
So our required equation would be 
Upon substituting our given values, we will get:



Since constant of proportionality is 665, so our equation would be
.
To find the number of days it will take to build a similar house with 5 workers, we will substitute
in our equation as:


Therefore, it will take 133 days for 5 workers to build a similar house.
4 = (r-2) t
8 = (r+2) t
4 = (r-2) * [8/(r+2)]
4 = (8r-16)/ (r+2) . . .multiply by 2
4r + 8 = 8r - 16
4r = 24
r = 6
hope this helps
22/7. It's basically the same thing
To change any percent into a decimal,
move the decimal point two places this way <=== .
8.7 % ==> 0.087