The r% of a quantity x is computed by dividing x in 100 parts, and considering r of such parts. So, the r% of the male is

and similarly, the r% of female is

The number of males decreased by this quantity, so now it is

and the number of female increased by this quantity, so now it is

we know that these two new counts are the same number, so we can build and solve the equality

Subtract 20 and add 0.3r from both sides:

Divide both sides by 0.5 to solve for r:

Let's check the answer
The 20% of 30 is
, while the 20% of 20 is 4. So, we are stating that
which is true because both expressions evaluate to 24.
Pretty sure the answer is k
1 foot = 12 inches
125 feet = 1,500 inches
60 feet = 720 inches
1,500 * 720 * 6 =
6,480,000 inches or 540,000 feet
we know there are 180° in π radians, how many degrees then in -3π/10 radians?
![\bf \begin{array}{ccll} degrees&radians\\ \cline{1-2} 180&\pi \\\\ x&-\frac{3\pi }{10} \end{array}\implies \cfrac{180}{x}=\cfrac{\pi }{~~-\frac{3\pi }{10}~~}\implies \cfrac{180}{x}=\cfrac{\frac{\pi}{1} }{~~-\frac{3\pi }{10}~~} \\\\\\ \cfrac{180}{x}=\cfrac{\pi }{1}\cdot \cfrac{10}{-3\pi }\implies \cfrac{180}{x}=-\cfrac{10}{3}\implies 540=-10x\implies \cfrac{540}{-10}=x \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ ~\hfill -54=x~\hfill](https://tex.z-dn.net/?f=%5Cbf%20%5Cbegin%7Barray%7D%7Bccll%7D%20degrees%26radians%5C%5C%20%5Ccline%7B1-2%7D%20180%26%5Cpi%20%5C%5C%5C%5C%20x%26-%5Cfrac%7B3%5Cpi%20%7D%7B10%7D%20%5Cend%7Barray%7D%5Cimplies%20%5Ccfrac%7B180%7D%7Bx%7D%3D%5Ccfrac%7B%5Cpi%20%7D%7B~~-%5Cfrac%7B3%5Cpi%20%7D%7B10%7D~~%7D%5Cimplies%20%5Ccfrac%7B180%7D%7Bx%7D%3D%5Ccfrac%7B%5Cfrac%7B%5Cpi%7D%7B1%7D%20%7D%7B~~-%5Cfrac%7B3%5Cpi%20%7D%7B10%7D~~%7D%20%5C%5C%5C%5C%5C%5C%20%5Ccfrac%7B180%7D%7Bx%7D%3D%5Ccfrac%7B%5Cpi%20%7D%7B1%7D%5Ccdot%20%5Ccfrac%7B10%7D%7B-3%5Cpi%20%7D%5Cimplies%20%5Ccfrac%7B180%7D%7Bx%7D%3D-%5Ccfrac%7B10%7D%7B3%7D%5Cimplies%20540%3D-10x%5Cimplies%20%5Ccfrac%7B540%7D%7B-10%7D%3Dx%20%5C%5C%5C%5C%5B-0.35em%5D%20%5Crule%7B34em%7D%7B0.25pt%7D%5C%5C%5C%5C%20~%5Chfill%20-54%3Dx~%5Chfill)