Respuesta :

Answer:

18.51 grams.

Step-by-step explanation:

We have been given the decay rate

We have general equation for decay which is:

[tex]y=a\cdot b^t[/tex];[tex]b=1-r[/tex]

Here, we are given with initial sample which is a=300

b=1-13%

And t is 20 years.

We will subatitute the values in the formula we get:

[tex]y=300\cdot (1-\frac{13}{100})^{20}[/tex]

[tex]\Rightarrow y=300(\frac{87}{100})^{20}[/tex]

[tex]\Rightarrow y=300(.87)^{20}[/tex]

After simplification we get y=18.51 grams.

The sample remain will be 18.51 grams.