Question

The selling price of 20 articles is equal to the cost price of 12 articles,the loss percent is

Answer 1

Let the selling price of 20 articles be €K

Let the cost price or 12 articles be €L

The cost price of each article is $\red{\boxed \frac{K}{20} }$ €

The selling price of each article is $\green{\boxed \frac{L}{12} }$ €

Now 20K = 12L

L = [ 20/12 ] K

$\blue{\leftarrow{\frac{L}{12} \: = \: \frac{5K}{36} }$

Now solve the rest yourself.