Initially, Marcus has a mixture of 5 parts white paint and 2 parts red paint, creating a ratio of red to white as follows:
- Red: 2 parts
- White: 5 parts
To find the original ratio of red to white, we express it as:
\[ \text{Ratio of Red to White} = \frac{\text{Red}}{\text{White}} = \frac{2}{5} \]
Next, Marcus adds one part of each color:
- New amount of red paint: \(2 + 1 = 3\) parts
- New amount of white paint: \(5 + 1 = 6\) parts
Now, we have:
- Red: 3 parts
- White: 6 parts
To find the new ratio of red to white, we calculate:
\[ \text{New Ratio of Red to White} = \frac{3}{6} = \frac{1}{2} \]
Thus, the new ratio of red to white is:
\[ \text{Ratio of Red to White} = 1 : 2 \]