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Wendy says that she can find the sale price of an item by multiplying by the difference of 100% and the percent of the sale. Is Wendy correct? Explain and give an example.

User Farhanjk
by
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2 Answers

4 votes

Answer:

Wendy is correct.

Step-by-step explanation:

Let's say an item costs $100, and the discount is 20%.

More common method:

The more common way to find the sale price is to find the amount of the discount, and then subtract it from the original price.

To find the amount of the discount, find 20% of $100:

20% of $100 = 0.2 * $100 = $20

The discount is $20.

Now we subtract $20 from $100 to find the sale price.

$100 - $20 = $80

The sale price is $80.

Wendy's method:

Now let's use Wendy's method on the same item and find its sale price.

The discount is 20%.

The difference between 100% and 20% is:

100% - 20% = 80%

Now we multiply the difference, 80%, by the original price.

80% * $100 = 0.8 * $100 = $80

The sale price is $80.

We used Wendy's method and we got the same answer.

Wendy is correct.

Step-by-step explanation:

The original price of the item is 100% of the price since 100% means the entire amount. The percent of the sale is x%. The item costs y.

Common method:

Sale price = y - x%y

Wendy's method:

Sale price = (100% - x%)y

Keep in mind that 100% = 1 and x% = 0.01x.

Common method:

y - x%y = y - 0.01xy

Sale price = y - 0.01xy

Wendy's method:

(100% - x%)y = (1 - 0.01x)y = y - 0.01xy

In both cases, the sale price is y - 0.01xy, so Wendy's method works.

User Rajan Rawal
by
3.9k points
5 votes

Answer:

Yes

Step-by-step explanation:

If it's a 20% discount,

She has to pay 100-20 = 80% of the marked prices.

User Ilya Ovesnov
by
5.5k points