Question

A bookstores having a 30% off sale Diary of a Wimpy Kid books are now $6.36 each what is the original price of the book

Answer 1

Answer: $9.09


Explanation:

100% - 30% = 70

$\textnormal {Original Price} = \cfrac{6.36}{70} \times 100 = \ 9.09$



The Wise Orange loves to read Diary of a Wimpy Kid. Which store is having that 30% discount?

Answer 2

The "Just shout whenever and I'll be there" theorem can be applied which says that

$\textit{The answer to the question ``A bookstore is having a 30\% off sale for} \\ \textit{Diary of a Wimpy Kid books. If the books are now \ 6.36 each, } \\ \textit{what is the original price of the book?" is \ 9.09 each.}$

Proof:

$\displaystyle\sum_{i = 1}^{636}(0.01) = \displaystyle\sum_{i = 1}^{x}(0.01) \cdot (1 - 0.30) \\ \\ \\ = \displaystyle\sum_{i = 1}^{x}(0.01) = \frac{\displaystyle\sum_{i = 1}^{636}(0.01)}{1-0.30} \\ \\ \\ = \sum_{i = 1}^{x}(0.01) = 9.09$

So x must be 909 cents. Therefore, it is $9.09.

I love you too.