Respuesta :
Joseph bought a book at full price for $15, then on the sale he got the second one for half price, but we know the second one was $10, and we know that's half the regular price, so the regular price must be twice as much of that, namely $20.
Joseph ended up paying only $25 for both, including the discount on the second, however if there wasn't any sale, he would have paid full price for both, namely 15 + 20, or 35.
so, he didn't pay $35, he paid $25, he saved 10 bucks.
if we take 35 to be the 100%, what is 10 off of it in percentage?
[tex]\bf \begin{array}{ccll} amount&\%\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 35&100\\ 10&p \end{array}\implies \cfrac{35}{10}=\cfrac{100}{p}\implies p=\cfrac{10\cdot 100}{35}[/tex]
Joseph ended up paying only $25 for both, including the discount on the second, however if there wasn't any sale, he would have paid full price for both, namely 15 + 20, or 35.
so, he didn't pay $35, he paid $25, he saved 10 bucks.
if we take 35 to be the 100%, what is 10 off of it in percentage?
[tex]\bf \begin{array}{ccll} amount&\%\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 35&100\\ 10&p \end{array}\implies \cfrac{35}{10}=\cfrac{100}{p}\implies p=\cfrac{10\cdot 100}{35}[/tex]
