To determine how much flour Oscar needs when using 1 tsp of yeast, we can set up a proportion based on the recipe given:
The recipe states:
- 3/4 tsp of yeast corresponds to 1/2 cup of flour.
We can express this as a ratio:
\[ \frac{3/4 \text{ tsp yeast}}{1/2 \text{ cup flour}} = \frac{1 \text{ tsp yeast}}{x \text{ cup flour}} \]
Cross-multiplying gives us:
\[ (3/4) \cdot x = (1/2) \cdot 1 \]
This simplifies to:
\[ (3/4) x = 1/2 \]
Next, we can solve for \( x \) by dividing both sides by \( 3/4 \):
\[ x = \frac{1/2}{3/4} \]
To divide by a fraction, we multiply by its reciprocal:
\[ x = \frac{1/2} \times \frac{4}{3} = \frac{4}{6} = \frac{2}{3} \]
So Oscar needs \( \frac{2}{3} \) cup of flour in order to maintain the same taste using 1 tsp of yeast.
The correct response is:
2/3 cup.