Question 328342
The easiest way to understand this problem is to use real numbers.  Let's say that the retail price of an object is $20.
So the local warehouse store offers 60% off retail:
20(1-0.60)= 20(0.4) = 8
So their everyday price for this object is $8.
During the sale, the store offers 70% off retail:
20(1-0.70) = 20(0.3) = 6
So their sale price is $6.
Now we want to find the percent discount the store is offering off its everyday price of $8.  We will use the same formula we have been using before:
E(1-D)=S  (where E = everyday price, D = percent discount, S = sale price)
8(1-D) = 6
1-D = 0.75
D = 0.25
So the store is offering a 25% discount off its everday price (answer D).