Originally Posted by

**harpazo** The price of a certain tv set is discounted by 10 percent, and the reduced price is then discounted by 10 percent. This series of successive discounts is equivalent to a single discount of

A. 20 percent

B. 19 percent

C. 18 percent

D. 11 percent

E. 10 percent

I decided to subtract 0.10 from 1. This led to 0.90.

I then decided to subtract 0.10 from 0.90. This led to 0.80. This is where you have gone wrong. You should be subtracting 10% of 0.90 (which is 0.09 not 0.10) from 0.90.

I concluded that the answer must by 20 percent because 20 percent plus 80 percent is 100 percent.

So, 1 - 0.20 = 0.80.

The book's answer is B, however. My answer is A. Why is my answer wrong?