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Name: Lawrence
Status: student
Age: 11
Location: N/A
Country: N/A
Date: N/A 


Question:
MY MOM IS ON MY CASE. SINCE HOLIDAY SEASON SHE IS ALWAYS ASKING ME WHAT THE PRICE OF SOMETHING IS WITH THE % DISCOUNT SIGN ON IT. HOW DO YOU DO DISCOUNT OR PERCENT OFF OF A PRICE? I DON'T WANT HER TO KNOW I DON'T REMEMBER SO A LOT OF TIMES I GO AWAY WHEN SHE IS NEAR THE RACK.



Replies:
It requires doing some math in your head. If the price says "$Y," and the discount tag says "X % off," the discounted price is $Y (1-X/100). In English, that means you multiply the percent off by the price, divide by 100, and subtract this from the original price.

For example, if the price tag says $24.95, and the sign says "10% off," 10 times 24.95 is 249.5. Divided by 100, that's 2.50 (rounded off), which you subtract from the original 24.95 to give approximately $22.50 (ok, $22.45, but the whole calculation is easier if you realize that $24.95 is very close to $25).

Richard Barrans Jr., Ph.D.
Chemical Separations Group


Hello,

A percentage simply means part per 100. So, one percentage of a hundred dollar is one dollar. Five percentage of a dollar is five cents.

So, if a carton of milk is normally $2.99 and it on sale for 10% discount, it means that you will take off 29.9 (actually 30) cents off the $2.99. Your net cost will be $2.69. When you get a discount of 10% it means that you pay only 90% of the regular cost.

I hope this help.

Good luck

Dr. Ali Khounsary
Advanced Photon Source
Argonne National Laboratory


``Per cent'' is French (roughly) for ``out of each hundred''. So a discount of 30 per cent is a reduction in the price of 30 pennies out of each hundred. Get it? Suppose the original price is 20 dollars = 2,000 pennies and the discount is 30 per cent. There are 20 hundreds of pennies in 2,000 pennies. For each of these we get a break of 30 pennies, so we get a total break of 20 x 30 = 600 pennies, or 6 dollars. Hence the discounted price is 20 - 6 = 14 dollars.

Grayce


Lawrence,

To do a quick calculation, subtract the discount percentage from 100, and use that number as a percentage multiplier to get the discounted price. For example:

say there is an item for $45.00, with a 15% discount.

100 minus 15 is 85.

Your new price would be 85% of the old price, so you can multiply the old price by 0.85, which is 85 percent written in decimal form.

0.85 times $45.00 is $38.25; this is the discounted price.

Thanks for using NEWTON, and many happy returns!

Richard R. Rupnik
Internal Quality Auditor
Lucent Technologies



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