Question

A radio is being discounted 20%.if the is sale of the radio is $51.44, what was the original price of the radio?

Answer 1

51.44 ÷ 0.8 = 64.3

So the original price was $64.30

Answer 2

     The Definition of Porcentage is given by:

$p= \frac{V_{x}}{V_{t}}$
 
     Where Vx is discounted value or increased, and Vt is total value. The discount decreases the "p" value.

$p= \frac{V_{x}}{V_{t}} \\ \frac{(100-20)}{100V_{x}} = \frac{1}{V_{t}} \\ V_{t}= \frac{51.44}{0.8} \\ \boxed {V_{x}=64.3}$

If you notice any mistake in my english, please let me know, because i am not native.