Question

Click the picture that I sent you

Answer 1

Answer: 1211.6585 years

Step-by-step explanation:

The equation for exponential growth is: $P=P_oe^{kt}$

• P: final population
• P₀: initial population
• k: rate of decay (or growth)
• t: time

Use the half life information to find k:

$\dfrac{1}{2}P_o=P_oe^{k(800)}\\\\\\\dfrac{1}{2}=e^{800k}\qquad \rightarrow \qquad \text{divided both sides by}\ P_o\\\\\\ln\bigg(\dfrac{1}{2}\bigg)=800k\qquad \rightarrow \qquad \text{applied ln to both sides}\\\\\\\dfrac{ln(\frac{1}{2})}{800}=k\qquad \rightarrow \qquad \text{divided both sides by 800}\\\\\\\large\boxed{-0.000867=k}$

Next, input the information (65% decayed = 35% remaining) and the k-value to find your answer.

$.35P_o=P_oe^{-0.000867t}\\\\\\.35=e^{-0.000867t}\\\\\\ln(.35)=-0.000867t\\\\\\\dfrac{ln(.35)}{-0.000867}=t\\\\\\\large\boxed{1211.6585=t}$