One-sixteenth

A Slovak resident uses a quarter of their average daily water consumption for personal hygiene, a twentieth for drinking, a sixteenth of the rest for washing dishes, and 105 litres for other activities. What is the average daily water consumption of a resident? If each of the 5.5 million residents reduced their daily consumption by 2%, how many hectolitres of water would be saved per day?

Final Answer:

d =  160 l
u =  176000 hl

Step-by-step explanation:

105 = d·(1 - 1/4-1/20-1/16·(1 - 1/4-1/20))

52.5d = 8400


d = 8400/52.5 = 160

d = 160

Our simple equation calculator calculates it.

$$\begin{gathered} n=5.5\cdot 10^6=5500000 \\ q=2\%=\frac{2}{100}=\frac{1}{50}=0.02 \\ {u}_1=d\cdot n\cdot q=160\cdot 5500000\cdot 0.02=17600000\text{l} \\ u=u_1\to \text{hl}=u_1:100\text{hl}=17600000:100\text{hl}=176000\text{hl}=176000\text{hl} \end{gathered}$$

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