Set 12: Linear Equations (Advanced)

Choice D is correct. Choice D is the correct answer. 1. Rates: Fill = $1 /4$, Drain = $-1/6$. 2. Equation: $\frac{1}{4} - \frac{1}{6} = \frac{1}{t}$ 3. Common Denominator (12): $\frac{3}{12} - \frac{2}{12} = \frac{1}{12}$ 4. Solve: $t = 12$ Choice B is incorrect because it results from an error in the solution process. Choice C is incorrect because it results from an error in the solution process. Choice A is incorrect because it results from an error in the solution process.