Radioactive material

A radioactive material loses 10% of its mass each year. What proportion will be left there after n=6 years?

Correct answer:

x =  0.5314

Step-by-step explanation:

$$\begin{gathered} n=6 \\ p=10\mathrm{\%} \\ q=1-p\mathrm{/}100=1-10\mathrm{/}100={\displaystyle \frac{9}{10}}=0.9 \\ x=q^n=0.9^6=0.5314 \end{gathered}$$

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