I'm stumped and need help with this question.

Question

A store sign reads "Take 75% off the original price when you take an additional 15% off the sale price, which is 60% off the original price." Is the store's sign accurate? Explain.

Answer 1

It depends on how you interpret "take an additional 15% off the sale price."  There are 2 ways to look at this.

 

p = original price

 

(1)

 

Take off 60% and you are left with 40% of p, which is 0.40p

 

0.40p = sale price

 

Take another 15% off the sale price, and you are left with 85% of the sale price.

 

0.85(0.40p) = sale price after discounting by 15% on top of the already discounted sale price

 

0.85(0.40p) = 0.34p = (1.00 - 0.66)p

 

The discount is really 66% off of the original price, in this case.

 

(2)

 

However, if they take BOTH the 60% and the 15% off of the original price, then the discounted price is

 

[1.00 - (0.60 + 0.15)]p = (1.00 - 0.75)p

 

In this case, the total discount really is 75%.  They probably really meant this case.

 

 

Answer 2

No. If you take off 60% at the sale price, 15% is not 15% of the orgianl price.



$100.00- 75%= $25.00 or





$100.00- 60%= $40.00



$40.00- 15%= $34.00