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\mathrm{V}(\mathrm{t})=200+4 \mathrm{t}, \mathrm{A}(\mathrm{t})=0.8 \mathrm{t}, \mathrm{C}(\mathrm{t})=\frac{0.8 \mathrm{t}}{200+4 \mathrm{t}} \rightarrow 0.8 / 4=0.2