Saturday, November 30, 2013

Which Discount is Best?

%%%% SALE %%%% DISCOUNT %%%% SAVE %%%%
When we buy an item "ON SALE" and the store gives
us a discount, say 25% (25% OFF), there are two ways
to find the FINAL PRICE.
I) Multiply the Original (LIST) Price by .25
and then subtract this number (25% of the List Price)
from the LIST PRICE. (Thus, using two steps.)
II) A one step process of Multiply the ORIGINAL PRICE
by .75 and having this product be the Final Price.
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With the above explanation, try this puzzle:

Which of the following two options would
save the most money?
Option #1: You can buy a $90.00
pair of shoes with a single discount of 29%.
OR
Option #2: The same pair of shoes can have
SUCCESSIVE DISCOUNTS of 10% and then 20%.

Try making you decision without performing
any arithmetic calculations.
After you make your choice, then actually
find the Final Prices under each Option.
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AFTER YOU HAVE ATTEMPTED THIS PUZZLE,
you can view the solution by copying  the yellow region below.
*************SOLUTION***************
You were probably surprised to find that
the one 29% discount was the best!

A more Algebraic explanation follows:

Let the LIST PRICE be represented by N.
The first of two discounts,10% off,
can be found by taking the
LIST PRICE TIMES .9 -> .9(N)
Multiplying this .9(N) times .8 results in
(.8)(.9)(N) or (.72)(N)
This is equivalent to an 28% Discount.
*************SOLUTION***************