IMathAS-libretexts

A chemist creates

\displaystyle {200}

milliliters of a

\displaystyle {50}\%

alcohol solution by combining a

\displaystyle {25}\%

alcohol solution with a

\displaystyle {75}\%

alcohol solution. If

\displaystyle {x}

represents the amount of the

\displaystyle {25}\%

alcohol solution used and

\displaystyle {y}

represents the amount of the

\displaystyle {75}\%

alcohol solution used, which of the following could be used to model the given infromation?

$\displaystyle {\left\lbrace\begin{array}{ccccc} {x}&+&{y}&=&{200}\\{25}{x}&+&{75}{y}&=&{50}\end{array}\right.}$
$\displaystyle {\left\lbrace\begin{array}{ccccc} {x}&+&{y}&=&{200}\\{0.025}{x}&+&{0.075}{y}&=&{100}\end{array}\right.}$
$\displaystyle {\left\lbrace\begin{array}{ccccc} {x}&+&{y}&=&{200}\\{2.5}{x}&+&{7.5}{y}&=&{100}\end{array}\right.}$
$\displaystyle {\left\lbrace\begin{array}{ccccc} {x}&+&{y}&=&{200}\\{0.25}{x}&+&{0.75}{y}&=&{100}\end{array}\right.}$
$\displaystyle {\left\lbrace\begin{array}{ccccc} {x}&+&{y}&=&{200}\\{0.25}{x}&+&{0.75}{y}&=&{50}\end{array}\right.}$