We can rewrite these percentages in decimal form. That what we can write an equation to solve. A percentage is a decimal that is multiplied by 100. So to reverse that, let us divide by 100:
[tex] \frac{80}{100}=0.8 [/tex] and [tex] \frac{20}{100} =0.2[/tex]
So we know that 80% = 0.8, and 20% = 0.2.
An equation we can write for the question is the following.
[tex]0.8*x=100[/tex], where x is the 'mystery' number.
So let us then solve for x:
[tex]x= \frac{100}{0.8}=125 [/tex]
So now we know that x = 125. Let us then create a second equation and solve the question:
[tex]0.2*125=y[/tex], where y is the answer that the question is looking for.
Let us then solve for y:
[tex]y=0.2*125=25[/tex].
So now we know that the answer to the question is 25.
