Respuesta :
It is given that there are two types of milk.
One is 3.5% and one is 0%.
Let the number of cups of 3.5% milk be x and the number of cups of 0% milk used be y.
The total should be 3 cups so it follows:
[tex]x+y=3\ldots(i)[/tex]It is also known that the resulting milk is 2% so it follows:
[tex]\begin{gathered} \frac{3.5}{100}x+\frac{0}{100}y=\frac{2}{100}(x+y) \\ \frac{3.5}{100}x=\frac{2}{100}(x+y) \end{gathered}[/tex]Multiply by 100 on both sides to get:
[tex]\begin{gathered} 3.5x=2(x+y) \\ 3.5x=2x+2y \\ 1.5x=2y \\ x=\frac{2}{1.5}y \\ x=\frac{2\times2}{1.5\times2}y \\ x=\frac{4}{3}y \end{gathered}[/tex]Substitute the value of (ii) in (i) to get:
[tex]\begin{gathered} x+y=3 \\ \frac{4}{3}y+y=3 \\ \frac{4+3}{3}y=3 \\ \frac{7}{3}y=3 \\ \frac{3}{7}\times\frac{7}{3}y=\frac{3}{7}\times3 \\ y=\frac{9}{7} \end{gathered}[/tex]Hence the quantity of 0% milk is 9/7 cups.
The quantity of 3.5% milk is given by:
[tex]\begin{gathered} x=\frac{4}{3}y \\ x=\frac{4}{3}\times\frac{9}{7} \\ x=\frac{12}{7} \end{gathered}[/tex]Hence the quantity of 3.5% milk is 12/7 cups.
