Butter

The same amount of butter is cut off from a cuboid-shaped block every day. After seven days, so much butter had been used that all its dimensions were halved.

a) What percentage of the butter is still left?

b) How many more days will the butter last if we continue to cut off the same amount every day?

Final Answer:

p =  12.5 %
d =  1 d

Step-by-step explanation:

$$\begin{gathered} V_1=abc \\ {V}_2=\frac{a}{2}\cdot \frac{b}{2}\cdot \frac{c}{2}=\frac{abc}{8}=\frac{V_1}{8} \\ p=100\cdot \frac{V_2}{V_1} \\ p=100\cdot \frac{1}{8}=\frac{100\cdot 1}{8}=\frac{100}{8}=\frac{25}{2}\%=12.5\% \end{gathered}$$

$$\begin{gathered} 7d\dots .7/8 \\ d=1=1\text{d} \end{gathered}$$

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