contestada

the color of paint used to paint a race car includes a mixture of yellow and green paint. scotty wants to lighten the color by increasing the amount of yellow paint 30%. if the new mixture contains 3.9 litres of yellow paint, how many litres of yellow paint did he use in the previous mixture

Respuesta :

let's say he had "x" liters, thus "x" is the 100% then.

then he increased the amount by 30% of that, so the new amount is really 100% + 30%, or 130%, which we know is 3.9 liters of yellow paint.

now, if 3.9 is the 130%, what is "x" anyway?

[tex]\bf \begin{array}{ccll} amount&\%\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ x&100\\ 3.9&130 \end{array}\implies \cfrac{x}{3.9}=\cfrac{100}{130}\implies x=\cfrac{3.9\cdot 100}{130}[/tex]