Janice has a pasta recipe that calls for 2 ounces of cheese for every 3 ounces of cooked pasta. Which graph shows this relationship between cheese and pasta?

A
.

The graph showing 'pasta' from 0 to 10 along the x-axis and 'cheese' from 0 to 10 along the y axis showing a upward facing line starting (0, 0) and passing through the points (2, 3), (4, 6) and (6, 9).

B.

The graph showing 'pasta' from 0 to 10 along the x-axis and 'cheese' from 0 to 10 along the y axis showing a upward facing line starting (0, 0) and passing through the points (3, 2), (6, 4), and (9, 6).

C.

The graph showing 'pasta' from 0 to 10 along the x-axis and 'cheese' from 0 to 10 along the y axis showing a upward facing line starting (0, 0) and passing through the points (2, 2), (4, 4), (6, 6), (8, 8) and (10, 10).

D.

The graph showing 'pasta' from 0 to 10 along the x-axis and 'cheese' from 0 to 10 along the y axis showing a upward facing line starting (0, 0) and passing through the points (5, 2) and (10, 4).

1 answer

To find the correct graph representing the relationship between cheese and pasta according to Janice's recipe, we need to establish the ratio provided.

The recipe calls for 2 ounces of cheese for every 3 ounces of cooked pasta. This can be expressed as a fraction:

\[ \frac{\text{cheese}}{\text{pasta}} = \frac{2}{3} \]

From this ratio, we can determine how much cheese corresponds to any amount of pasta. If we let \( p \) represent the amount of pasta (in ounces) and \( c \) represent the amount of cheese (in ounces), we can write the relationship as:

\[ c = \frac{2}{3}p \]

Now we can check each of the provided graphs to see which one fits this equation.

Graph A passes through:

  • (0, 0)
  • (2, 3)
  • (4, 6)
  • (6, 9)

Checking the points:

  1. For \( p = 2 \): \[ c = \frac{2}{3} \cdot 2 = \frac{4}{3} \quad (\text{but it shows } 3) \]
  2. For \( p = 4 \): \[ c = \frac{2}{3} \cdot 4 = \frac{8}{3} \quad (\text{but it shows } 6) \]
  3. For \( p = 6 \): \[ c = \frac{2}{3} \cdot 6 = 4 \quad (\text{but it shows } 9) \]

Graph B passes through:

  • (0, 0)
  • (3, 2)
  • (6, 4)
  • (9, 6)

Checking the points:

  1. For \( p = 3 \): \[ c = \frac{2}{3} \cdot 3 = 2 \quad (\text{correct, shows } 2) \]
  2. For \( p = 6 \): \[ c = \frac{2}{3} \cdot 6 = 4 \quad (\text{correct, shows } 4) \]
  3. For \( p = 9 \): \[ c = \frac{2}{3} \cdot 9 = 6 \quad (\text{correct, shows } 6) \]

Graph C: This graph passes through

  • (0, 0)
  • (2, 2)
  • (4, 4)
  • (6, 6)
  • (8, 8)
  • (10, 10)

However, it shows a 1 to 1 ratio, which does not match our recipe.

Graph D:

  • (0, 0)
  • (5, 2)
  • (10, 4)

Checking the points:

  1. For \( p = 5 \): \[ c = \frac{2}{3} \cdot 5 = \frac{10}{3} \quad (\text{not } 2) \]
  2. Similarly, for \( p = 10 \): \[ c = \frac{2}{3} \cdot 10 = \frac{20}{3} \quad (\text{not } 4) \]

Thus, the only graph that accurately represents the relationship of \( c = \frac{2}{3}p \) is Graph B.

So the correct answer is:

B