Toilets

Federal law requires all residential toilets sold in the United States to use no more than 1 3/5 gallons of water per flush. Before this legislation, conventional toilets used 3 2/5 gallons of water per flush. Find the amount of water saved in one year by a family flushing the toilet 22 times daily if one conventional toilet is replaced with a new low-flow one. (1 year = 365 days)

Correct answer:

y =  14454 gal

Step-by-step explanation:

$$\begin{gathered} n=22\cdot 365=8030 \\ {V}_1=3\frac{2}{5}=3+\frac{2}{5}=\frac{3\cdot 5+2}{5}=\frac{15+2}{5}=\frac{17}{5}=3.4\text{gal} \\ {V}_2=1\frac{3}{5}=1+\frac{3}{5}=\frac{1\cdot 5+3}{5}=\frac{5+3}{5}=\frac{8}{5}=1.6\text{gal} \\ V=V_1-V_2=\frac{17}{5}-\frac{8}{5}=\frac{17-8}{5}=\frac{9}{5}=1.8\text{gal} \\ y=n\cdot V=8030\cdot \frac{9}{5}=\frac{8030\cdot 9}{5}=\frac{72270}{5}=14454\text{gal} \end{gathered}$$

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