To solve the first problem regarding Christian's haircut:
- The cost of the haircut is $18.
- Christian gave a 20% tip on that amount.
- To find the tip: \[ 20%, \text{of}, 18 = 0.20 \times 18 = 3.60 \]
- Now, to find the total amount paid, add the tip to the original haircut cost: \[ 18 + 3.60 = 21.60 \]
Therefore, the total amount Christian paid for the haircut is C. $21.60.
For the second problem regarding the pasta recipe:
The recipe calls for 2 ounces of cheese for every 3 ounces of pasta. This indicates a ratio of cheese to pasta, which can also be represented as:
\[ \frac{\text{cheese}}{\text{pasta}} = \frac{2}{3} \]
From this ratio, if you have 'x' ounces of pasta, then the ounces of cheese 'y' can be calculated as:
\[ y = \frac{2}{3}x \]
To identify the suitable points:
- If pasta = 0 ounces, cheese = 0 ounces (point (0, 0)).
- If pasta = 3 ounces, cheese = 2 ounces (point (3, 2)).
- If pasta = 6 ounces, cheese = 4 ounces (point (6, 4)).
- If pasta = 9 ounces, cheese = 6 ounces (point (9, 6)).
From these calculations, we can see that the correct graph based on the points generated will be:
B. The graph showing 'pasta' from 0 to 10 along the x-axis and 'cheese' from 0 to 10 along the y axis showing an upward facing line starting (0, 0) and passing through the points (3, 2), (6, 4), and (9, 6).