Question

On a factory floor ,20 out of every 170 toy robots is defective. What percent of the toy robots are defective

Answer 1

First, you would need to create an equation for this problem. Let x represent the unknown percent. 
$\frac{20}{170}$ = $\frac{x}{100}$

Next, you would cross multiply. 
170x = 2,000

Now, all you would need to do is isolate the x. To do this, you would divide both sides of the equal sign by 170. 
x = 11.7647058824%

20 is 11.7647058824% or, rounded, 12% of 170. 

I hope this helps!