The half-life of a specific radioactive compound is 15 years. The equation used to model this half-life is y = 200(1/2)t/15, where t represents time. Currently, there are 200 pounds of this substance remaining. Determine approximately how much of the substance remains after 82 years. Round to the nearest tenth of a year.

Question

The half-life of a specific radioactive compound is 15 years. The equation used to model this half-life is  y = 200(1/2)t/15,  where t represents time. Currently, there are 200 pounds of this substance remaining. Determine approximately how much of the substance remains after 82 years.  Round to the nearest tenth of a year.

anonymous · Answer

replace $t$ by $82$ and use a calculator

anonymous · Answer

that is, compute 
$$\large 200\times \left(\frac{1}{2}\right)^{\frac{82}{15}}$$

anonymous · Answer

i got 546.6666667

anonymous · Answer

no it should be small

anonymous · Answer

make sure to raise one half to the power first, then multiply by 200 last

anonymous · Answer

https://www.wolframalpha.com/input/?i=200*%281%2F2%29^%2882%2F15%29

anonymous · Answer

so its 5

anonymous · Answer

says round to the nearest tenth