For a certain isotope, at the end of every 29-year period, the mass o…

Question

Prompt

For a certain isotope, at the end of every 29-year period, the mass of a sample of the isotope has decayed to half its mass at the beginning of the 29-year period. The function

s (t) = 216 (0.5)^{\frac{t}{29}}

gives the approximate mass of this isotope, in grams, that remains t years after a 216-gram sample starts to decay. Which statement is the best interpretation of

s (3 \cdot 29) = 27

in this context?

The mass of the sample is approximately 27 grams 3 years after the sample starts to decay.

The mass of the sample is approximately 27 grams 3 29-year periods after the sample starts to decay.

The mass of the sample is approximately 3 grams 27 29-year periods after the sample starts to decay.

The mass of the sample is approximately 31 years after the sample starts to decay.