Question

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

A. $12.86
B. $64.30
C. $41.15
D. 65.05

I know to multiply 51.44 by the percentage as a decimal then add it ( decimal= 0.2 ), but i get 61?

Answer 1

You can do a proportion:
Example:
If the sale price was $20, it is 80% of the original price
and if $X is 100% of the original price, we write

$20: 80%
X=100%

and solve for X by cross multiplication:
X=\(\large \frac{$20*100\%}{80\%}\)=$25 (this is an example)
You can apply the same method to your problem.

Answer 2

OHHH. okay thank you

Answer 3

@mathmate

Answer 4

hmm? im trying to apply it to my problem but it is diffitcult so i divide 51.44 by .80 i get 41.15, which is one of the choices but how could the original price be lower than the discount?

Answer 5

Or you can use algebra.
Let x = original cost of radio then: .20x would equal the discount (20%)
Sale price will equal original price Minus the discount OR
51.44 =x - .2x
.8x = 51.44

Answer 6

thank you!

Answer 7

You're welcome, that is what we are here for.

Answer 8

It is B, thank you for your help!!

Answer 9

Did you follow with understanding. I forgot to mention that $51.44 was the "on sale" or discounted price.

Answer 10

@Kevinz You were almost there, but unfortunately you have multiplied by 0.8 instead of dividing.
If you had made a division, you would have got $64.3 instead of $41.15.
"there are different ways to skin a bear!"

Answer 11

@mathmate Yes thank you both, I learned that there was an inverse operation in this and that you could find the answer several ways.